Offices:  DREXEL  BUILDING, 
Philadelphia,  Pa.,  U.  S.  A. 


LEADING  MANUFACTURERS 

OF  FINE 


Driers,  Japans 

and  Varnishes. 


Having  patented,  and  the  most  advanced  methods 
and  machinery,  the  best  equipped  company  in  the 
world  for  filling  special  requirements  in  DRIERS, 


JAPANS  and  VARNISHES,  we  especially  solicit 
the  patronage  of  wholesale  dealers. 


/c? 

The  Stilwell'Bierce 

&  Smith-Vaile  Co. 

DAYTON,  OHIO,  U.  S.  A. 

MANUFACTURERS  OF 

A 

“THE  SMITH-VAIEE” 
CORN,  LINSEED  and 

COTTON  OIL  MACHINERY, 

STEAM  AND  POWER  PUMPING  MACHINERY, 
FILTER  PRESSES, 
“STILWELL”  Feed  Water  Heaters, 

THE  “VICTOR”  TURBINE. 


PRATT  &  LAMBERT 


(INCORPORATED.) 


manufacturers  of 


Crushers'  Driers, 
Ink  Driers, 


Paint  Driers, 

Oil  Qoth  Driers 


AND 


Varnishes  for  All  Purposes. 


Offices : 


WOODBRIDGE  BUILDING, 

‘  'JOHN  &  WILLIAM  STS.,  NEW  YORK. 
370-378  26th  ST.,  CHICAGO. 

21  ST.  ANTOINE  ST.,  MONTREAL. 

Factories : 

LONG  ISLAND  QTY,  N.  Y.  CHICAGO,  ILL.  MONTREAL, 

CANADA. 


II. 


A  PRACTICAL  MANUAL 


Linseed  Oil  Manufacture 

And  Treatment. 


Varnish  Manufacture, 

Superior,  Medium, 
and  Cheap  Grades. 


By  JOHN  BANNON. 


Published  by 

THE  NATIONAL  PROVISIONER  PUBLISHING  CO., 


NEW  YORK  AND  CHICAGO. 


Czo/'^S 

tP 

/  'X 

/  ^^7 


MANUFACTURED  BY 


BROOKLYN,  NEW  YORK. 


IV. 


THE  GETTY  Cti^TER 

UBRART 


1 


PREFACE. 


^  I  "HERB  is  no  system  in  any  line  of  manufacturing  which  can- 
*  not,  in  some  particular,  he  improved;  nor  is  there  any  oil 
miller  so  proficient  in  the  business  that  he  cannot  learn  something 
of  value  from  another  of  the  craft.  This  must  of  necessity  be  the 
case,  for  the  reason  that  there  is  no  person  who  can  hope  to  com¬ 
pass  every  known  thing  in  any  given  manufacturing  industry  in 
his  own  personal  experience,  however  varied  or  practical  it  may 
have  been.  Realizing  this  fact,,  the  author  of  this  volume,  during 
twenty  years  of  practical  oil  milling,  has  endeavored  to  acquire  all 
the  information  that  to  him  seemed  important  relative  to  the  busi¬ 
ness,  same  being  acquired  by  personal  experiments  and  close  ob¬ 
servation.  A  variety  of  valuable  points  are  covered  and  treated 
in  this  volume,  and  since  an  article  is  of  no  value  unless  it  is  un¬ 
derstood,  the  author  has  paid  special  regard  to  simplicity,  and  his 
aim  has  been  to  make  his  style  of  expression  simple,  and,  there¬ 
fore,  readily  understood. 

Concerning  the  text  of  the  work,  with  regard  to  oil  milling, 
as  already  observed,  same  is  the  result  of  writer’s  personal  exper¬ 
ience,  while  with  regard  to  varnish  making,  etc.,  the  matter  which 
appears  is  merely  the  result  of  research  and  extracts  from  well- 
known  authorities. 

The  book,  in  the  main,  was  written  under  the  most  difficult 
conditions,  and  not  with  a  view  to  merit  encomiums  with  regard 
to  its  literary  qualifications. 

JOHN  BANNON, 

June  lo,  1897. 

365  Decatur  St.,  Brooklyn,  N.  Y. 


Entered  according  to  Act  of  Congress  in  the  year  1897,  by 
THE  NATIONAL  PROVISIONER  PUBLISHING  CO. 
OF  New  York  and  Chicago, 

ROBERT  GANZ  &  COMPANY,  PROPRIETORS, 

In  the  Office  of  the  Librarian  of  Congress  at  Washington 


ROBERT  OA.NZ. 


THE 


Dr.  J.  H.  SENNER. 


National  Profisioier  Palilislii  Coiaiy, 

ROBERT  GANZ  &  CO.,  Proprietors. 

NEW  YORK  :  CHICAGO  : 

384-386  PEARE  STREET,  No.  11  RIAETO  BUIEDING, 

Cor.  of  Beekman.  Adjoining  Board  of  Trade. 


The  national  PROYISIONER, 

THE  ORGAN  OF  THE 

Provision  and  Meat  Industries 

OF  THE 

. 

UNITED  STATES  AND  CANADA. 


Chicag:o,  New  York,  'Roston,  Philadelphia,  Cincinnati,  Kansas 
City,  .^t.  Eouis,  Eondon,  England. 


PUBLISHED  EVERY  SATURDAY. 


SUBSCRIPTION  PRICE: 

In  the  United  States  and  Canada,  -  -  SS4.00  Per  Annum. 
In  Eoreig^n  Countries,  -----  $>6.00  Per  Annum. 

(Postage  Prepaid.) 


PUBLISHERS  OF  THE 

Pork  Packers’  Handbook  and  Directory 

of  the 

MEAT  AND  PROVISION  TRADES. 

440  Pages.  Price,  $10.(X). 

The  Manufacture  of  Cottonseed  Oil 

AND 

ALLIED  PRODUCTS. 

9.5  Pages.  Price,  $3.00, 


VII. 


The  above  cut  shows  our  Combined  Water-Cooled  Mill  and  Mixer.  Mill  is 
entirely  independent  of  the  Mixer.  Either  can  be  stopped  or  started  without 
stopping  the  shaft  by  a  clutch.  Made  single  or  in  gangs  of  two  or  three.  It  is 
really  the  most  perfect  mill  yet  placed  on  the  market.  Very  substantial,  neat  and 
compact. 

C.  W.  H.  CARTER.  C.  HARRIS  CARTER.  O.  G.  CARTER. 

C.  W.  H.  CARTER, 

26  Rose  St.,  New  York. 
ESTABLISHED  OVER  A  QUARTER  OF  A  CENTURY. 

All  Kinds  of  Burnt  Varnishes  for 

I 

i 

Printing  and  Lithographic  Inks* 

- ALSO - 

Burnt  Plate  Oils  for  Steel  and  Copper  Plate  Inks.  Special 
Varnishes  and  Oils.  Special  Drier  IMade  Especially  for  Inks. 


viri. 


EDWARD  CRAVEN. 


J.  A.  CAMERON. 


PRESS  CLOTH. 

Sugden  Press  Bagging  Co., 

‘manufacturers  of 

CLOTH  FOR  ALL  KINDS  OF  OIL  PRESSES. 

None  but  first  quality  cloth  manufactured.  Every 
roll  guaranteed  against  imperfections  in  stock  or  weav¬ 
ing. 

A  large  stock  of  Linseed  and  Cottonseed  Press 
Cloth  constantly  on  hand  to  ensure  prompt  delivery. 
Special  attention  paid  to  the  manufacture  of  odd 
widths  and  weights  for  special  purposes. 


Represented  in  the  Southern  States  by 

MR.  HENRY  CHARNOCK, 

629  Gravier  Street,  -  -  New  Orleans,  La. 


Factory  and  Office  at  West  Chelmsford,  IMass. 

Telegrams  to  Lowell,  Mass.  Correspondence  Solicited. 


IX. 


THE  “JOHNSON”  FILTER  PRESS.^^^ 


JOHN  JOHNSON  &  CO., 

Franklin  Square  and  Cherry  Street, 

NEW  YORK  aTY,  N.  Y. 


Makers  and  Patentees  oe  .  .  . 

Filter  Presses 


For  the  Separation  of  Solids  from  Liquids  by  Filtra¬ 
tion  and  all  Appliances  for  Working  Them. 


SPECIAL  OIL  AND  VARNISH  FILTERS. 

FILTER  PRESS  CLOTHS  and  FILTER  PRESS  PUMPS. 


Send  for  Catalug^ue. 

X. 


THE  I^ANUFACTURE  OF  LINSEED  OIL. 


CONCERNING  THE  VARIOUS  CLASSES  OF  FLAXSEED. 


Conditions  Requisite  in  Linseed  Oil  to  Produce  Best  Results. 


As  linseed  oil  is  a  very  essential  constituent  of  a  good 
paint  or  varnish,  to  which  latter,  among  other  features, 
it  imparts  the  property  of  elasticity,  too  much  care  can¬ 
not  be  devoted  to  the  selection  of  an  article  of  warranted 
genuineness. 

A  brief  outline  of  the  most  efficient  and  economical 
method."  necessary  in  its  manufacture,  together  with  a 
consideration  of  the  requisite  features  which  it  must 
possess  to  be  suited  to  the  special  requirements  peculiar 
to  varnish  making,  will  be  appropriate  at  this  time. 

As  pointed  out  in  the  foregoing  paragraph,  the  primary 
condition  essential  in  linseed  oil  intended  for  use  in  varn¬ 
ish  or  paint  making  of  standard  qualities  consists  in  its 
absolute  purity,  that  is  to  say,  linseed  oil  of  commerce 
manufactured  by  the  most  approved  appliances  from  the 
purest  obtainable  crude  material.  The  seed  from  which 
the  oil  is  made  should  be  full-grown  and  mature,  the  im¬ 
purities,  which  consist  of  mineral  substances,  grains  of 
wheat,  maize,  etc.,  etc.,  and  all  vegetable  matter  foreign 
to  the  genuine  linseed,  whether  of  an  oleaginous  or  non- 
oleaginous  nature,  should  be  eliminated  as  carefully  as 
the  circumstances  warrant. 

The  seed  from  which  linseed  oil  is  usually  made  in 
England,  having  been  nurtured  by  the  soil  and  clime  of 

1 


2 


THE  MANUFACTURE  OF  LINSEED  OIL. 


the  East  Indies,  which  region  possesses  elementary  con¬ 
ditions  peculiarly  favorable  to  the  cultivation  of  linseed, 
a  mature  and  well-developed  grain  are  some  of  its  charac¬ 
teristic  features.  Russian  or  American  seed  in  an  unripe 
condition  is  not  infrequently  met  with,  and  as  large 
lots  of  these  varieties  of  seed  are  at  times  imported,  for 
the  two-fold  purpose  of  taking  advantage  of  the  low 
figures  which  occasionally  rule  the  foreign  markets  and 
to  off-set  a  probably  high  quotation  with  regard  to  the 
East  India  product,  something  concerning  the  nature  of 
these  seeds  may  be  read  with  interest.  However  well  the 
manufacturing  process  may  be  carried  out,  an  inferior  oil 
yield  is  always  'obtained  from  an  unripe  seed,  while  the 
quality  at  best  is  of  a  secondary  nature.  Oil  of  this 
description  is  unsuited  to  the  requirements  of  varnish 
making,  and  should  be  carefully  avoided.  Unless  sub¬ 
jected  to  extraordinary  treatment  in  the  clarification, 
chemical  and  mechanical  refining,  filtering,  and  finally 
in  maturation,  the  use  of  an  oil  of  this  variety  very  fre¬ 
quently  proves  disastrous.  Many  reasons  may  be  adduced 
in  support  of  this  averment.  By  reason  of  the  fact  that 
the  mucilaginous  matter,  or  incipient  vegetable  forma¬ 
tion  of  the  seed,  deprived  of  adequate  time  for  complete 
development  by  solar  and  other  elementary  influences, 
or,  as  is  frequently  the  case,  owing  to  the  restraining  ef¬ 
fects  of  an  uncongenial  climate,  the  growth  of  the  oil- 
yielding  substance  is  retarded,  and  an  abnormal  propor¬ 
tion  of  imperceptible  fibrous  substance  is  pressed  out 
with  the  oil.  It  is  this  latter  substance  which  the  varnish 
maker  abhors  as  he  would  contagion.  Its  presence  in  an 
oil  intended  for  use  in  varnish  making  is  highly  deleter¬ 
ious,  and  it  is  only  after  the  oil  has  been  submitted  to  a 
high  temperature  that  this  objectionable  substance  be¬ 
comes  apparent.  This  peculiar  combination  of  gummy 
or  fibrous  substance  may  be  easily  detected  by  submit- 


THE  MANUFACTURE  OF  LINSEED  OIL. 


3 


ting  a  sample  of  the  oil  to  the  fire  test  in  a  glass  testing 
tube,  and  after  about  thirty  hours’  repose,  its  presence 
will  be  indicated  by  cloudy  masses  suspended  in  the  oil. 

Oil  made  from  the  average  seed  of  the  ripe  American 
or  Russian  variety,  contains  a  much  larger  proportion 
of  natural  moisture  than  that  of  the  East  India  seed,  but, 
subjected  to  skillful  treatment,  superior  varnishes  are 
regularly  made  with  it.  So  fierfect  is  the  manipulation 
made  by  several  of  the  large  crushing  concerns  in  the 
United  States,  in  the  preparation  of  this  oil  for  use  in 
varnish  making,  that  it  is  difficult  even  for  an  expert  to 
distinguish  between  the  genuine  East  India  seed  oil  and 
the  oil  made  from  the  domestic  variety  of  seed.  This  fact 
is  of  peculiar  significance  when  it  is  considered  that  the 
oil  from  the  East  India  seed  always  commands  a  higher 
figure  than  that  from  the  American  product,  the  former 
commanding  20  cents  per  gallon  over  the  latter  at  this 
time.  Whether  rightly  or  wrongly,  it  is  considered  that 
oil  drawn  from  the  most  superior  variety  of  Russian  or 
American  seed,  however  skillfully  manufactured,  or 
manipulated  afterwards,  ranks  as  a  lower  grade  than  oil 
from  the  East  India  seed,  from  a  varnish  standpoint. 
Nevertheless,  with  correct  treatment,  it  is  regularly 
demonstrated  that  very  superior  varnishes  are  made  from 
oil  of  this  description,  unexceptionable  alike  in  their 
durability  and  covering  properties. 

An  average  sample  of  full-grown  American  or  Russian 
seed  contains  from  four  to  seven  per  cent  of  moisture  and 
from  three  to  six  per  cent  of  foreign  matter,  which  in¬ 
cludes  mineral  substances,  wild  seed  of  an  oleaginous  or 
non-oleaginous  nature,  etc.,  etc. 

A  variety  of  seed  which  is  largely  imported  from  the 
East  Indies  to  England,  and  known  as  Calcutta  seed, 
contains  a  high  percentage  of  foreign  matter,  but  the 
seed  itself  is  invariably  full-grown  and  mature,  and  the 


4 


THE  MANUFACTURE  OF  LINSEED  OIL. 


elimination  of  the  objectionable  matter  leaves  a  product, 
which  under  skillful  treatment  produces  an  excellent  oil, 
generally  superior  and  much  lighter  in  color  than  that 
made  from  seed  grown  in  more  variable  climates.  Seed 
which  is  imported  from  the  district  of  which  Bombay  is 
the  shipping  port,  is  comparatively  dear,  and  but  little 
screening  is  required  to  prepare  it  for  the  manufacturing 
processes.  It,  however,  contains  a  peculiar  vegetable 
substance,  triangular  in  form,  as  hard  as  flint  almost,  and 
about  the  size  of  an  ordinary  grain  of  seed,  in  variable 
proportions,  which  is  dififlcult  to  remove  by  the  ordinary 
mesh  of  the  revolving  screen,  owing  to  its  similarity  in 
size  to  the  seed  with  which  it  is  intimately  associated. 
Being  of  a  non-oleaginous  nature,  its  presence  does  not 
affect  the  quality  of  the  oil,  but  in  the  rolling  process  its 
propensity  to  become  wedged  between  a  driving  and 
frictional  chilled  roll — the  two  sides  of  the  triangular¬ 
shaped  substance  forming  the  wedge,  and  the  third  side 
the  base — very  frequently  clogs  the  entire  machine  and 
temporarily  brings  the  crushing  operation  to  a  standstill. 
Another  peculiarity  of  this  variety  of  seed  consists  in  the 
large  proportion  of  light  yellow  seed  always  present  in  a 
parcel,  while  the  grain  is  of  a  uniform  size,  plump  and 
mature. 

The  percentage  of  moisture  present  in  the  East  Indian 
seed  is  fractional,  and  the  oil  yield  exceeds  that  of  the 
best  variety  of  seed  grown  elsewhere.  About  thirty-two 
or  thirty-three  per  cent  of  oil  is  considered  a  satisfactory 
yield  from  the  average  Russian  or  American  variety 
seed,  but  to  obtain  this  proportion,  the  seed  must  be  ripe . 
and  the  manufacturing  processes  unexceptionable.  The 
mature  and  well-developed  seed  cultivated  in  the  East 
Indies  yields  oil  more  freely  under  treatment,  the  usual 
proportion  under  normal  conditions  being  about  two  per 
cent  over  that  of  the  best  of  other  varieties.  This  oil 


THE  MANUFACTURE  OF  LINSEED  OIL. 


5 


being  pale  in  color  in  its  natural  condition,  when  refined, 
and  sufficiently  aged,  is  especially  prized  by  the  varnish- 
maker.  Cold  drawn  oil  from  any  description  of  seed  is 
much  lighter  in  color  than  that  produced  by  artificial 
heat,  the  latter  being  the  only  practical  means,  in  con¬ 
junction  with  the  auxiliary  processes,  to  obtain  the  maxi¬ 
mum  yield.  Oil  made  from  ripe  seed  and  subsequently 
subjected  to  efficient  treatment  presents  a  peculiar  aspect 
in  the  sample  phial,  at  once  indicative  of  its  purity  and  the 
general  properties  indispensable  in  the  production  of  a 
first-class  varnish.  It  will  appear  limpid  and  brilliant, 
sweet  to  the  taste,  with  very  little  smell,  and  the  test  will 
disclose  the  fact  that  it  is  specifically  lighter  than  impure 
oil  generally — although  in  the  detection  of  an  impure 
oil  this  is  not  a  reliable  guide — and  when  clarified  dries 
quickly  and  firmly,  and  does  not  materially  change  the 
color  of  the  varnish  when  made.  In  specific  gravity  it 
may  be  noted  that  even  pure  oil  varies  somewhat,  the 
average  being  0.935,  but  the  range  is  from  0.932  to 
0.937  at  the  standard  temperature  of  60°  F.  Its  solidifi¬ 
cation  is  obtained  by  reducing  the  temperature  to  27°  C. 

A  light-colored  oil  is  especially  desired  by  varnish  and 
white  lead  manufacturers  and  to  each  the  choice  of  a  pure 
article  is  of  the  greatest  moment.  The  growing  tendency 
to  use  finely  bleached  oils  is  becoming  more  marked 
yearly. 

Concerning  the  productions  of  an  absolutely  pure  oil 
in  large  quantities  without  containing  the  least  vestige  of 
foreign  matter,  it  must  be  said  that  it  is  impracticable  by 
reason  of  the  fact  that  the  complete  removal  of  the  im¬ 
purities  would  necessitate  the  employment  of  innumer¬ 
able  hands,  a  circumstance  which  would  involve  such 
enormous  expense  that  its  consideration  is  out  of  the 
question.  On  a  small  scale,  for  empirical  purposes,  in 
the  laboratory  it  is  frequently  done,  but  the  tedium  in- 


6 


THE  MANUFACTURE  OF  LINSEED  OIL. 


separable  to  the  entire  removal  of  all  extraneous  matter 
by  digital  means — the  only  possible  method  of  ac¬ 
complishing  the  purpose — becomes  almost  intolerable. 
On  a  recent  occasion  the  complete  removal  of  about 
seven  per  cent  of  such  matter  from  a  sample  of  seed, 
weighing  about  200  grammes,  occupied  the  writer  five 
hours  of  close  application. 

Taking  this  as  a  basis,  it  would  require  many  weeks  to 
clean  or  thoroughly  remove  such  matter  from  a  single 
bushel! 

The  oil  extracted  from  this  small  sample  of  really  pure 
seed,  which  was  divested  of  thd  slightest  trace  of  outside 
matter,  being  filtered,  and  allowed  two  weeks’  repose, 
showed  exceptionally  light  color,  and  its  drying  proper¬ 
ties  demonstrated  surpassing  excellence  when  applied  to 
the  surface  of  the  testing  glass. 

The  most  impure  seed  may  be  screened  sufficiently  to 
meet  the  requirements  of  all  practical  purposes,  and  a 
high  percentage  of  dirt  and  other  matter  in  the  seed  may 
be  reduced  to  from  one  and  one-half  to  two  per  cent  as  a 
minimum  quantity.  There  are  on  the  market  to-day  ex¬ 
cellent  screens,  varying  in  capacity  from  200  to  500 
bushels  per  twenty-four  hours,  their  use  in  the  produc¬ 
tion  of  a  superior  oil  being  beyond  question.  The  com¬ 
paratively  diminutive  size  of  the  foreign  seed,  exclusive 
of  maize  or  wheat  grains,  facilitates. their  separation  from 
the  genuine  seed,  when  Screens  or  sieves  of  a  certain 
gauge  or  mesh  are  used. 

Seed  containing  these  deleterious  substances  naturally 
produces  an  inferior  oil  proportionate  to  the  percentage 
present,  while  the  oil  which  has  been  extracted  from 
pure  seed,  that  is,  seed  which  has  been  subjected  to  a 
preliminary  sifting  process,  and  from  which  all  extran¬ 
eous  substances  have  been  removed,  as  far  as  modern  de¬ 
vices  will  permit,  is  at  all  times  an  object  of  especial  con- 


THE  MANUFACTURE  OF  LINSEED  OIL. 


7 


sideration  to  the  practical  varnish  maker.  A  certain  pro¬ 
portion  of  non-drying  oil  extracted  from  the  oleaginous 
substances  is  always  present  in  an  oil  made  from  impure 
seed.  The  product  acts  most  injuriously  on  the  dry¬ 
ing  properties  of  the  whole,  unless  special  and  prolonged 
treatment  be  accorded  it.  Under  the  most  favorable 
treatment  such  oil  is  undesirable  for  the  manufacture  of 
a  superior  varnish  by  reason  of  the  fact  that,  although  an 
extended  period  of  time  be  permitted  for  repose,  during 
which  the  vegetable  and  fine  mineral  substances  may  be 
effectively  precipitated,  the  non-drying  fluid  will  remain 
irremovably  in  solution  with  the  linseed  oil,  partly  owing 
to  the  similarity  of  specific  gravities  and  other  affinities, 
the  result  proving  a  defective  product.  Under  no  circum¬ 
stances  should  oil  of  this  nature  be  set  aside  for  ultimate 
use  in  the  varnish  manufactory.  No  artificial  conditions 
which  may  be  superimposed  on  an  oil  of  this  description, 
can  elevate  it  to  the  standard  of  an  oil  made  from  pure 
seed  which  has  been  allowed  a  sufficient  settling  period. 
The  impure  oil  under  the  sulphuric-acid-refining  process 
shows  a  large  percentage  of  loss,  the  charred  and  pre¬ 
cipitated  impurities  being  in  proportion  to  the  extent  of 
its  impure  condition. 

When  linseed  cake  as  a  feeding  product  commands  a 
good  price  and  the  concurrent  demand  for  oil  is  slow,  and 
at  a  price  where  a  very  narrow  margin  of  profit  is  ob¬ 
tainable,  many  of  the  small  crushers  improve  the  oppor¬ 
tunity  by  working  off  any  variety  of  seed  which  comes 
their  way  without  preliminary  screening;  thus  the  extran¬ 
eous  substances  all  go  to  increase  the  weight  of  the  cake, 
and  the  oil  is  sold  on  the  market  as  a  pure  article. 

It  mav  further  be  added  that  there  are  oil  mills  which 
turn  out  just  such  oil  right  along,  hence  the  necessity 
of  adopting  the  only  precautionary  measure  possible  to 
insure  the  obtaining  of  a  pure  oil,  that  is,  to  purchase  di¬ 
rect  from  a  reputable  crusher. 


8 


THE  MANUFACTURE  OF  LINSEED  OIL. 


ABSOLUTE  REQUIREMENTS  IN  THE  MANUFACTURE  OF  A 

PURE  LINSEED  OIL. 

Briefly,  it  may  be  stated  that  the  general  principles 
which  govern  the  manufacture  of  a  pure  oil  are  composed 
of  four  distinct  processes: 

1st. — Thorough  screening. 

2d. — Fine  grinding. 

3d. — Correct  manipulation  of  the  ground  material  in 
the  treating  kettle,  with  regard  to  temperature,  moisture, 
etc.,  etc. 

4th. — Adequate  pressure  for  the  extraction  of  the  oil 
from  the  prepared  material. 

Subjected  to  from  3,500  tbs.  to  4,000  tbs.  pressure  per 
square  inch,  the  oil  is  squeezed  out  from  the  ground  and 
heated  material,  and  falls  from  rear  of  the  press  to  suit¬ 
able  receiving  tanks  beneath. 

At  this  stage — two  or  three  hours  after  the  oil  is  made 
— the  first  important  step  in  the  treatment  of  the  oil  takes 
place.  It  consists  in  slow  filtration  and  is  accomplished 
by  passing  the  oil  under  light  pressure  through  filtering 
material,  prior  to  being  pumped  into  the  large  storage 
tanks  to  await  shipment.  The  filtering  material  referred 
to  is  held  in  position  in  the  chambers  of  a  press  formed 
by  circular-formed  concave  plates,  between  each  succes¬ 
sive  two  of  which  cloths  of  different  textures  are  placed, 
through  which  latter  the  oil  is  caused  to  pass,  leaving  the 
footy  matter  on  surface  of  the  cloths.  There  are  various 
sizes  and  forms  of  filter  press,  particulars  of  which  will 
be  hereafter  given  in  detail.  A  reprehensible  system 
with  regard  to  filtration  is  maintained  in  some  instances, 
which  consists  in  raising  the  temperature  of  the  oil  im¬ 
mediately  after  being  made  to  about  200  degrees  Fahren¬ 
heit  to  facilitate  its  transmission  through  the  filtering 
material.  The  heating  is  effected  by  means  of  a  coil  of 


THE  MANUFACTURE  OF  LINSEED  OIL. 


9 


steam-piping  arranged  in  circular  form  around  the  in¬ 
ner  side  of  the  receiving  tank,  placed  immediately  below 
the  presses.  In  this  abnormal  condition  the  oil  is  forced 
through  the  filter  press.  A  sample  of  oil  taken  as  it  flows 
from  the  filter  press  presents  the  aspect  of  a  well-settled 
liquid;  but  the  appearance  is  deceptive,  owing  to  the  fact 
that  many  substances  in  the  oil,  'with  regard  to  foreign 
matters,  and  that  unctuous  extraction  of  the  oleaginous 
proportion  thereof,  become  soluble  and  imperceptible  in 
the  oil  when  the  latter  is  heated — although  they  assume 
the  opposite  physical  condition  when  the  oil  is  cold — 
and  these  objectionable  substances  are  thus  carried 
through  the  filtering  material  with  the  oil.  Examination 
of  a  sample  of  oil  taken  under  these  conditions  and  al¬ 
lowed  a  few  days’  settling  will  at  once  -demonstrate  the 
amount  of  precipitated  matter  which  under  normal  con¬ 
ditions  should  have  been  retained  by  the  filtering  ma¬ 
terial. 

Instead  of  eliminating  from  90  to  96  per  cent  of  the  im¬ 
purities — the  normal  proportion  under  correct  manage¬ 
ment — only  from  60  to  80  per  cent,  and  not  infrequently 
a  still  lesser  proportion,  is  retained  by  the  filtering  ma¬ 
terial,  the  surplus  extraneous  matter  passing  off  with  the 
oil,  a  circumstance  which  the  filtering  apparatus  was 
especially  designed  to  obviate.  An  equal  length  of  time 
is  requisite  for  the  complete  precipitation  of  footy  matter 
to  produce  a  clear  oil  under  these  conditions,  as 
though  the  filtering  machine  were  not  in  operation.  The 
true  solution  of  this  difficulty  consists  in  permitting  the 
oil  to  cool  prior  to  filtration.  It  is  an  egregious  mistake 
not  only  to  increase  the  temperature  of  the  newly-made 
oil  for  the  purpose  of  facilitating  the  filtration  process, 
but  also  to  permit  its  passage  through  the  filter  press  at 
the  temperature  which  it  retains  by  reason  of  the  heat 
applied  to  the  crushed  seed  in  heating  kettle,  to 


10 


THE  MANUFACTURE  OF  LINSEED  OIL. 


promote  the  oil  yield.  The  licjuid  should  be  allowed 
sufficient  time  to  cool  in  cone-shaped  receiving  tanks, 
situated  immediately  beneath  the  hydraulic  presses,  the 
tanks  to  be  further  utilized  not  only  as  temporary  recep¬ 
tacles  for  the  newly-manufactured  oil,  but  to  facilitate  the 
correct  return  of  the  regular  oil  yield  of  each  watch,  as 
well  as  for  the  deposition  of  the  mealy  matter.  Sufficient 
pitch  should  be  given  to  the  cone  to  permit  of  the  thick, 
sludgy  substance  working  down  to  the  point  from  which 
it  may  be  drawn  off  in  concentrated  form  at  stated  in¬ 
tervals,  The  accumulation  of  this  substance  may  be 
drawn  off  in  this  manner  with  great  facility,  and  a  com¬ 
paratively  clear  oil  is  continuously  passing  from  the 
upper  part  of  the  tank,  through  the  overflow  pipe,  the  lat¬ 
ter  entering  the  tank  several  inches  from  the  top.  The 
thick,  mealy  substance  is  then  slowly  reworked,  and 
much  labor  is  saved  by  securing  it  in  this  practical  man¬ 
ner,  as  compared  with  the  old  system,  which  consisted 
of  pumping  direct  to  storage  tanks,  the  oil,  with  its  ad¬ 
mixture  of  meal,  thereby  involving  unpleasant  and 
arduous  labor  in  frequent  tank  cleaning. 

It  is  customary  in  ordinary  mills  to  have  small  square 
tanks  to  receive  the  oil  as  it  flows  from  the  presses,  and 
from  which  the  meal^  is  removed  daily,  but  tlieir  utility  is 
much  inferior  to  the  cone-shaped  tanks  referred  to. 
Under  the  most  favorable  conditions,  a  certain  propor¬ 
tion  of  the  mealy  matter  will  have  been  taken  up  by  the 
pump,  and  together  with  the  oil,  will  be  pumped  to  stor¬ 
age  tanks.  With  ordinary  care  this  is  practically  impos¬ 
sible  in  the  new  design,  and  the  sum  total  of  attention 
which  the  latter  demands  to  ensure  a  very  effective 
separation  of  the  oil  from  the  foots  is  the  withdrawal 
of  the  latter  twice  or  thrice  daily  by  the  attendant. 
Probably  two  or  three  pailfuls  from  each  tank  on  each 
watch  will  amply  suffice.  In  the  removal  of  the  foots 


THE  MANUFACTURE  OF  LINS'EED  OIL. 


11 


from  the  square  receiving  tanks,  necessarily  a  large  pro¬ 
portion  of  the  liquid  is  withdrawn;  also,  all  of  which 
must  be  again  worked  off  uniformly,  and  its  distribution, 
which  must  be  effected  by  the  exercise  of  good  judgment, 
very  frequently  occupies  the  entire  time  of  a  mill  hand. 
The  cone-shaped  settling  and  receiving  tank  very  mater¬ 
ially  lessens  the  amount  of  foots  to  be  reworked,  for  the 
reason  that  there  is  absolutely  no  oil  withdrawn  with  the 
foots,  and  the  solidarity  of  the  latter  facilitates  its  admix¬ 
ture  with  the  pulverized  parings,  or  cake  trimmings,  be¬ 
neath  the  small  set  of  millers  now  generally  used  for  that 
purpose.  Mention  must  be  made  of  another  very  desirable 
feature  of  this  form  of  tank,  which  consists  in  the  very 
material  improvement  in  the  filtration  process  superin¬ 
duced  by  its  use.  The  precipitation  of  the  foots  in  the 
cone-shaped  tank,  in  the  first  instance,  lessens  the  amount 
of  work  the  filter  press  would  otherwise  have  to  perform, 
and  lengthens  the  intervals  between  cleaning  times; 
that  is,  the  chambers  of  the  filter  press  will  not  require 
opening  for  the  removal  of  the  caked  meal  so  frequently 
as  under  other  conditions,  while  the  filtering  process  is 
maintained  under  less  pressure  and  in  a  much  more  per¬ 
fect  manner.  The  writer  has  constructed  a  number  of 
these  tanks  within  the  past  few  years,  the  result  proving 
in  every  instance  of  the  -most  satisfactory  nature. 

A  heated  and  rapidly-filtered  oil  requires  almost  as 
much  time  for  repose  to  effect  complete  precipitation  of 
the  extraneous  matter  as  though  it  had  not  been  filtered, 
and  the  good  results  derived  from  filtration  under  ef¬ 
ficient  management  are  thereby  lost.  The  filtration  of  a 
cold  oil  consumes  considerably  more  time  than  an  oil  the 
normal  temperature  of  which  has  been  increased.  As 
previously  pointed  out,  the  heated  oil  passes  rapidly 
through  the  filtering  material  under  light  pressure,  but 
the  cold  oil,  that  is,  oil  at  the  normal  temperature,  cannot 


12 


THE  MANUFACTURE  OF  LINSEED  OIL. 


be  filtered  so  expeditiously  by  reason  of  the  fact  that  the 
retention  of  the  almost  entire  proportion  of  the  footy 
matter  by  the  filtering  material  tends  to  clog  the  latter, 
and  fill  the  chambers  more  frequently  than  is  the  case 
when  the  heated  oil  is  filtered.  The  filtration  process  is 
therefore  necessarily  slower,  with  regard  to  an  oil  pos¬ 
sessing  a  normal  temperature,  but  superior  in  quality  to 
that  treated  at  an  abnormal  temperature,  while  the  manu¬ 
facturer  has  the  satisfaction  of  knowing  that  the  oil 
turned  out  under  these  conditions  is  of  surpassing  excel¬ 
lence,  a  circumstance  which  adequately  compensates  for 
the  incidental  expenses  attached  thereto. 

The  expense  involved  in  cleaning  cloths  and  removing 
the  caked  substance  from  the  clogged  chambers  of  the 
press  is  very  much  more  than  off-set  by  the  saving  ef¬ 
fected  in  the  prevention  of  the  accumulation  of  the  foots 
in  the  large  storage  tanks.  Where  the  cone-shaped  tank 
and  filter  press  are  operated  conjointly  in  a  seed-crushing 
establishment,  an  oil  storage  tank  may  be  filled  and 
emptied  regularly  for  years  without  the  necessity  of 
tank-cleaning  becoming  apparent,  while  without  their 
use  every  two  or  three  months  a  removal  of  the  accumu¬ 
lated  foots  becomes  am  absolute  necessity.  To  those  who 
know  the  amount  of  manual  labor  involved  in  the  clean¬ 
ing  of  a  linseed  oil  storage  tank,  the  number  of  barrels 
resting  on  their  chimes,  with  the  heads  removed,  neces¬ 
sary  to  contain  the  foots  removed  therefrom,  and  which 
when  filled  to  about  three-quarters  of  their  capacity  must 
await  their  turn  for  weeks  to  be  reworked,  their  presence 
lending  a  general  air  of  confusion  and  untidiness  to  the 
entire  manufacturing  premises,  the  expense  and  other 
unpleasant  incidental  concomitants,  it  will  be  superfluous 
to  add  further  description.  These  two  important  ad¬ 
juncts  to  oil  milling — the  cone-shaped  receiving  tank  and 
filter  press — have  removed  many  of  the  objectionable 


THE  MANUFACTURE  OF  LINSEED  OIL. 


13 


features  in  the  manufacturing  processes  heretofore  un¬ 
avoidable,  and  no  well-regulated  mill  can  be  oper¬ 
ated  without  them,  A  pressure  up  to  70  pounds 
per  square  inch  may  be  maintained  consistent  with 
good  work,  at  which  point  the  pump  should  be 
shut  off,  the  press  allowed  to  drain,  opened,  and 
the  footy  matter  removed.  The  inlet  flow  should 
be  regulated  so  that  a  uniform  stream  of  oil  may 
be  passed  through,  and  the  fact  must  always  be  borne  in 
mind,  the  slower  the  liquid  is  passed  through  the  filtering 
material,  the  more  superior  the  filtration  process  will  be. 
The  temperature  of  the  oil  should  not  exceed  75°  Fahr, 
The  only  instance  where  crude  oil  may  be  heated  to 
advantage  is  where  more  than  one  filtration  process  is 
performed;  the  first  run  of  oil  depositing  the  thick  sedi¬ 
ment  on  the  filtering  material  and  passing  through,  after 
which,  when  allowed  time  to  assume  its  normal  tempera¬ 
ture,  is  again  subjected  to  a  slow  filtration,  producing  a 
clear  and  pure  oil.  In  the  preparation  of  a  refined  oil, 
and  not  infrequently  that  of  a  varnish  oil,  recourse  to  two 
or  three  filtering  processes  is  regularly  made. 

After  the  lapse  of  sufficient  time  for  repose,  say  three 
months,  the  oil  is  specially  treated  for  varnish  making. 
In  the  treatment  accorded  linseed  oil  intended  for  use  in 
varnish  making,  every  precaution  which  practical  experi¬ 
ence  has  found  essential  to  adopt  must  be  carefully  ob¬ 
served  to  ensure  satisfactory  results.  Until  within  a 
comparatively  recent  period  the  business  of  preparing 
linseed  oil  for  use  in  varnish  making  formed  a  distinct 
and  separate  branch  of  industry  from  that  of  the 
manufacture  of  the  crude  product,  but  with  the  progres¬ 
sive  spirit  of  the  times,  a  number  of  the  leading  crushers 
in  England  and  the  United  States  have  been  constrained 
to  enlarge  their  sphere  of  action  by  supplementing  their 
original  calling  with  that  of  refining,  boiling  and  general 


14 


THE  MANUEACTURE  OF  LINSEED  OIL. 


manipulation  of  the  oil  within  the  confines  of  their  indi¬ 
vidual  manufacturing  precincts. 

In  past  generations  the  duties  of  the  seed  crusher 
terminated  with  the  manufacture  of  the  raw  product,  but 
the  modern  seed  crusher  to  keep  pace  with  the  times, 
must  not  only  be  conversant  with  the  most  approved  ma¬ 
chinery  and  manufacturing  processes,  but  a  knowledge 
of  chemistry  is  indispensable,  in  as  far  as  it  appertains  to 
the  oil  itself,  together  with  the  ingredients  used  in  its 
manipulation,  to  meet  the  various  requirements  essential 
in  paint  and  varnish  making. 

The  underlying  principles  which  control  the  diversified 
aspect  of  linseed  oil  in  its  changing  physical  properties 
must  be  thoroughly  understood  when  under  treatment, 
the  exact  nature  of  the  latter,  with  regard  to  temperature, 
chemical  and  mechanical  action,  consistent  with  the  use 
to  which  the  product  will  be  ultimately  assigned. 

A  thorough  knowledge  of  this  important  industry  in 
all  its  phases  has,  therefore,  resolved  itself  into  a  science, 
in  which  category  it  may  be  justly  placed. 

Very  many  methods  of  preparing  oil  for  the  needs  of 
varnish  makers  diave  been  successively  adopted  and,  in 
turn,  abandoned  by  reason  of  the  introduction  of  a  more 
recent  expedient  which  gave  promise  of  better  results. 

There  are  a  number  of  methods,  now  in  regular  use, 
for  the  preparation  of  linseed  oil  well  suited  to  the  re¬ 
quirements  of  varnish  making,  each  manufacturer  hav¬ 
ing  special  processes  and  formulas  which  accord  with  his 
individual  views  of  the  necessities  of  the  case,  the  knowl¬ 
edge  of  which  he  jealously  guards  as  an  inviolable  trade 
secret. 


Linseed  Oil  Fecnliarities— Consideration  of  the  Yarions  I'lethods 
Used  To-Day  to  Produce  Best  Results— The  Oil 

Percentage  in  Cake. 

'  ^ 

Among  the  methods  hereafter  described,  in  which 
reference  will  be  made  to  the  latest  and  most  approved 
known  in  the  preparation  of  linseed  oil  for  varnish  pur¬ 
poses,  many  valuable  hints- will  be  given  relative  to  their 
practical  demonstration  of  efficiency,  the  .careful  con¬ 
sideration  of  which,  it  is  presumed,  will  prove  serviceable 
and  of  material  consequence  to  the  practical  and  progres¬ 
sive  varnish  maker. 

In  the  treatment  of  linseed  oil  for  use  in  varnish-mak¬ 
ing,  the  primary  object  in  view  is  to  facilitate  its  assimila¬ 
tion  with  the  gums,  possessing  good  siccative  properties, 
and  other  inherent  qualities,  characteristic  of  a  pure  oil. 
The  first  step  in  the  manufacturing  process  consists  in  pro¬ 
curing  an  oil  of  pure  make,  of  mature  age,  and  a  known 
brand.  The  chief  difficulty  which  the  operator  experi¬ 
ences  with  an  imperfectly  prepared  oil  consists  in  the 
“breaking”  or  separating  proclivity  inseparable  from  an 
impure  oil.  In  an  impure  or  imperfectly  prepared  oil,  the 
separation  of  the  fine  vegetable  matter,  which  becomes 
apparent  when  the  temperature  has  reached  a  point  be¬ 
tween  400°  or  500°  Fahr.,  is  not  the  only  difficulty  which 
confronts  the  varnish  maker,  for  the  reason  that  the 
gummy  substance  which  assumes  definite  formation  at 
this  temperature,  has  a  marked  tendency  to  discolor  the 
batch  under  treatment,  and  which,  by  the  undesirable 
combination,  is  sometimes  irrecoverably  spoiled. 

It  is,  therefore,  of  paramount  importance  to  thorough¬ 
ly  eliminate  this  mucilaginous  matter,  by  whatever  means 
employed,  if  a  good  varnish  is  to  be  produced.  If  the 
combination  of  mechanical  and  chemical  processes  prove 
ineffective  by  reason  of  the  fact  that  the  operative  may 

15 


16 


THE  MANUFACTURE  OF  LINSEED  OIL. 


not  be  conversant  with  the  precise  and  exact  mode  of 
application  requisite  to  procure  the  desired  results,  which 
the  least  deviation  therefrom  will  assuredly  demonstrate, 
recourse  may  be  had  to  ageing  of  the  product,  which,  if 
not  discolored  by  previous  operations,  will  in  every  in¬ 
stance  prove  satisfactory. 

The  fine  substance  which  remains  suspended  in  the  oil, 
to  the  eradication  of  which  the  energies  of  the  chemist 
and  practical  oilman  have  been  devoted,  is  imperceptible 
in  the  crude  oil  and  in  many  of  the  prepared  oils,  but  its 
presence  is  plainly  demonstrated  in  the  test  tube,  in  from 
twenty-four  to  thirty  hours  subsequent  to  heating. 

Thousands  of  gallons  of  varnish  are  regularly  made 
with  oil  containing  this  substance,  the  presence  of  which 
may  be  unknown  to  the  operator  in  the  preliminary  pro¬ 
cesses  of  varnish  making,  the  manufactured  product 
proving  in  many  respects  of  a  satisfactory  nature,  but  it 
has  been  incontrovertibly  demonstrated  that  the  oil  from 
which  this  substance  has  been  entirely  removed  produces 
a  superior  product,  viewed  from  every  phase  of  the  ques¬ 
tion. 

That  proportion  of  the  crude  oil  which  possesses  greater 
specific  gravity  than  that  of  the  pure  product,  is  the 
substance  which  should  be  eradicated.  The  difference  in 
specific  gravity  is  not  apparent  until  the  lapse  of  a  certain 
time  subsequent  to  heating,  when  its  presence  becomes 
plainly  visible,  and  the  advantages  deriving  from  the 
mechanical  and  chemical  combination  when  effective, 
consist  in  the  precipitation  of  this  substance  without 
having  recourse  to  the  usually  extended  period  of  set¬ 
tling,  otherwise  absolutely  indispensable. 

Extended  time  will  invariably  remove  this  substance  in 
an  oil  treated  by  the  sulphuric  acid  process,  but  a  crude 
oil,  however  long  permitted  to  settle,  will  “break”  when 
submitted  to  a  high  temperature.  As  previously  stated, 


THE  MANUFACTURE  OF  LINSEED  OIL. 


17 


its  elimination  may  be  effectively  procured  by  simultan¬ 
eous  chemical  and  mechanical  treatment. 

Many  reasons  have  been  advanced  as  to  why  this  sub¬ 
stance  has  become  more  troublesome  than  in  former 
years,  and  for  the  removal  of  which  much  greater  pains 
must  be  taken  than  was  heretofore  necessary.  Probably 
the  most  feasible  reason  which  may  be  cited  is.that  owing 
to  the  perfection  to  which  hydraulic  pressure  has  been 
brought  in  its  application  to  the  crushed  seed,  and  by 
means  of  which  the  uniform  and  maximum  amount  of 
pressure  may  be  maintained  unrelaxed  during  the  entire 
pressing  operation,  a  fine  substance  of  a  mucilaginous  or 
gummy  nature,  much  more  delicate  in  formation  than  the 
ordinary  vegetable  matter,  is  pressed  out  with  the  oil. 

At  a  normal  temperature  its  presence  in  a  specially- 
prepared  oil  is  uncertain,  owing  to  the  similarity  of  spe¬ 
cific  gravity,  and  not  until  the  oil  has  been  submitted  to  a 
high  temperature,  and  subsequent  to  a  brief  repose,  is  its 
presence  indicated,  the  proportions  of  which  determine 
the  efficiency  of  the  refining  process. 

Less  than  a  generation  ago,  the  percentage  of  oil  left 
in  the  cake,  subsequent  to  the  application  of  hydraulic  pres¬ 
sure,  was  as  high  as  13  per  cent,  but  nowadays  the  stand¬ 
ard  amount  is  placed  at  7  per  cent,  a  very  material  differ¬ 
ence.  An  excess  of  oil  over  this  latter  amount  is  con¬ 
sidered  as  just  so  much  loss — as  oil — a  slightly  redeeming 
feature  in  the  matter  being  the  weight  of  the  surplus  oil 
left  in  the  cake  realizes  the  same  market  value  as  the  cake 
itself,  thus  the  difference  in  value  between  the  oil  and 
the  cake  is  lost  to  the  manufacturer. 

It  is  this  increased  amount  of  oil  extracted  by  superior 
mechanism  which  contains  the  fine  flocculent  substance, 
the  removal  of  which  becomes  of  such  importance  in  the 
manufacture  of  superior  varnishes.  To  this  circumstance 
is  due  the  suggestion  that  the  admixture  of  the  oil  which 


18 


THE  MANUFACTURE  OF  LINSEED  OIL. 


flows  freely  before  the  limit  of  pressure  has  been  reached 
with  that  extracted  under  the  maximum  pressure  should 
be  obviated,  thus  rendering  a  large  proportion  of  the 
newly-made  oil  free  from  the  fine  vegetable  matter  al¬ 
ways  present  in  the  oil  obtained  under  the  latter  con¬ 
ditions. 

Several  of  the  leading  seed  crushers  in  the  United 
States  have  adopted  a  system  by  means  of  which  the  oil 
extracted  under  the  light  pressure  may  be  effectually 
separated  from  that  produced  under  the  maximum  pres¬ 
sure,  and  without  relaxation  of  the  latter,  the  results 
proving  of  such  a  satisfactory  nature  as  to  warrant  its 
continuance.  The  oil  obtained  by  the  first  flow  is  re¬ 
served  for  refined  oil,  which  includes  varnish  oil;  the  resi¬ 
due — after  the  ordinary  clarification  and  filtration  pro¬ 
cesses  have  been  executed — is  finally  utilized  for  boiled 
oil,  or  in  the  various  ways  in  which  the  product  is  applied. 
Instead  of  one  tank,  which  is  usually  placed  immediately 
beneath  a  set  of  presses  to  receive  the  newly-made  oil, 
two  are  set  side  by  side.  Into  tank  number  one,  the  first 
run  of  oil  yielded  under  light  pressure  is  caused  to  flow, 
but  as  soon  as  the  reduced  volume  demonstrates  the  fact 
that  the  light  pressure  has  reached  the  limit  of  useful¬ 
ness  in  expressing  the  fluid,  and  prior  to  the  application 
of  the  heavy  pressure,  the  spout  leading  from  the  small 
trough  which  receives  the  oil  as  it  falls  from  the  press,  is 
changed  to  number  two  tank,  into  which  the  succeeding 
or  second  run  of  oil  is  discharged.  Thus,  the  oil  which  is 
obtained  under  the  prolonged  and  maximum  pressure  is 
in  no  manner  associated  with  that  procured  by  the  initial 
pressure,  the  system  being  maintained  continuously,  the 
volume  flowing  from  the  successive  charges  of  the  press 
being  divided  as  shown.  The  seed  being  of  good  cpiality 
and  thoroughly  screened,  and  the  manufacturing  pro¬ 
cesses  maintained  throughout  in  an  efficient  manner,  the 


THE  MANUFACTURE  OF  LINSEED  OIL. 


19 


oil  from  the  first  drawing,  subsequent  to  the  usual  pre¬ 
liminary  treatment,  invariably  proves  to  be  an  excellent 
varnish  oil. 

■« 

The  oil  extracted  subsequent  to  the  first  run  contains  a 
high  percentage  of  the  objectionable  vegetable  matter, 
and  its  complete  removal  in  the  production  of  a  superior 
varnish  oil  becomes  difficult  of  accomplishment,  even 
under"  the  most  auspicious  circumstances. 

It  may  be  cited,  as  an  exceptional  instance,  that  one  of 
the  seed-crushing  establishments  in  England,  by  means 
of  fine  rolling,  thorough  cooking  and  greater  pressure 
on  the  material  than  heretofore  used,  contrives  to  reduce 
the  percentage  of  oil  in  the  cake  to  a  point  below  four. 
The  tenacity  and  durability  of  the  new  press  bagging 
material,  recently  introduced,  renders  possible  the  fore¬ 
going  surprising  results.  In  the  United  States  several 
of  the  oil  mills  regularly  manufacture  cake  with  a  per¬ 
centage  of  oil  rarely  exceeding  five. 

The  increased  proportion  of  fine  vegetable  matter 
which  is  unavoidably  pressed  out  by  this  more  perfect 
method,  will  be  readily  understood,  and  the  use  of  pre¬ 
cautionary  measures  of  separating  the  grades  amply  war¬ 
ranted. 

The  adaptability  of  the  second  run  to  the  peculiar  re¬ 
quirements  of  boiled  oil  are  readily  demonstrated  when 
applied  to  a  surface,  subsequent  to  suitable  treatment. 
Unlike  oil  intended  for  use  in  varnish  making,  to  suit 
the  views  of  the  average  consumer,  boiled  oil  must 
possess  a  deep  color.  This  physical  property  is  attained 
by  the  application  of  heat  and  air  in  conjunction  with 
driers,  the  chemical  ingredients  of  which,  acting  as  pre- 
cipitants  of  the  feculent  matter,  and  after  the  expiration 
of  about  two  weeks,  produce  an  excellent  boiled  oil,  deep 
in  color  and  transparent  to  the  view.  The  presence  of  an 
abnormal  proportion  of  the  extraneous  substance,  due 


‘20 


THE  MANUFACTURE  OF  LINSEED  OIL. 


to  improper  filtration  or  insufficient  subsidence,  mani¬ 
fests  itself  in  an  oil  under  treatment  by  discoloring-  the 
latter.  Hence  the  necessity  of  carefully  avoiding  the  use 
of  an  oil  for  varnish  purposes  possessing  the  objection¬ 
able  features  referred  to.  It  has  been  ascertained  beyond 
doubt,  that  oil  obtained  during  the  period  when  the 
hydraulic  system  is  strained  to  its  utmost  capacity  con¬ 
tains  a  large  proportion  of  imperceptible  substances 
which  remain  in  solution  in  the  oil  when  cold,  passing 
out  freely  with  the  latter  from  the  filter  press,  to  appear 
in  tangible  form  subsecpient  to  the  application  of  heat, 
in  light  fragmentary  particles.  A  peculiarity  of  the  latter 
consists  in  the  fact  that  their  presence  is  not  indicated 
until  about  thirty  hours  after  the  heating  process.  An 
absolutely  sure  method  of  eradicating  this  substance,  the 
presence  of  which  is  imperceptible  in  some  prepared  oils, 
consists  in  heating  the  latter  to  about  350°  Fahrenheit, 
and  after  forty-eight  hours’  repose  subjecting  them  to 
slow  filtration.  About  thirty  hours  subsequent  to  the 
heating  process  the  fine  substance  assumes  material  form 
and  readily  deposits  on  the  surface  of  the  filtering 
medium.  This  additional  treatment  may  be  conducted 
without  discoloring  the  oil,  the  reverse,  a  bleached  oil, 
being  produced  thereby.  Oil  treated  by  the  alkali  or 
sulphuric  acid  process,  subjected  to  a  supplementary 
heating  process,  of  brief  duration,  becomes  bleached,  but 
owing  to  the  expense  involved,  except  in  special  cases 
where  fanciful  prices  warrant  its  use,  it  is  impracticable. 

The  Russian-made  linseed  oil,  from  thirteen  to  fifteen 
per  cent  of  which  is  guaranteed  to  be  revealed  on  cake 
analysis,  with  suitable  treatment,  is  peculiarly  fitted  for 
varnish  purposes.  But  the  Russian  varnish  maker  is  slow 
to  appreciate  the  advantage  here  presented,  while  the 
national  demand  for  a  superior  product  is  not  sufficiently 
pronounced  to  prove  a  stimulus  to  further  progress. 


THE  MANUFACTURE  OF  LINSEED  OIL. 


21 


The  fundamental  principles  which  should  govern  the 
preliminary  operations  in  the  treatment  of  an  oil  intended 
for  use  in  varnish  making  consist  in  thorough  clarifica¬ 
tion  and  filtration  in  the  first  instance,  followed  by  a  sec¬ 
ondary  process,  by  means  of  which  the  suspended  matter 
may  be  eliminated,  and  the  oil  bleached  concurrently. 
The  purification  and  bleaching  processes  are  effected  by 
the  use  of  sulphuric  acid  or  alkali,  generally,  and  after 
the  expiration  of  a  suitable  period  for  the  subsidence  of 
the  charred  vegetable  matter,  washing  is  resorted  to  for 
the  removal  of  the  last  vestiges  of  impurities.  Two  or 
three  days’  additional  repose  is  then  permitted  the  oil, 
after  which  the  water  is  drawn  off  and  the  clear  oil 
pumped  into  a  steam-jacketed  kettle  fitted  with  agitators, 
and  submitted  to  the  influence  of  a  temperature  not  ex¬ 
ceeding  200°  Fahrenheit.  This  effectually  removes  the 
moisture  present  in  the  oil,  while  the  air  which  by  means 
of  forcing  pumps  is  simultaneously  blown  into  the  mass 
of  agitated  oil,  oxidizes  and  imparts  “body”  thereto  by 
lessening  its  fluidity.  A  well-made  oil  treated  in  the 
foregoing  manner,  with  correct  proportions  of  the  purify¬ 
ing  agents,  and  strict  adherence  to  the  regular  mechani¬ 
cal  auxiliary  processes,  will  produce  a  liquid  of  uniform 
consistency,  bleached  and  transparent,  which  will  not 
“break,”  or  separate,  or  evolve  irregular  action  when 
undergoing  treatment  in  the  production  of  a  superior 
varnish.  Slow  filtration  and  subsequent  repose  materially 
improve  and  ultimately  produce  a  perfect  varnish  oil.  To 
impart  to  the  oil  a  still  further  bleached  aspect  than 
commercial  requirements  ordinarily  call  for,  the  influence 
of  solar  light  is  sometimes  brought  into  requisition,  sub¬ 
sequent  to  the  chemical  manipulation  and  immediately 
before  the  final  filtration  process.  Flat  copper-lined 
tanks  placed  immediately  beneath  extensive  glass  roofs 
are  used  for  this  purpose ;  the  oil  placed  therein  being  of 


22 


THE  MANUFACTURE  OF  LINSEED  OIL. 


shallow  depth  to  facilitate  the  action  of  the  solar  influence. 

The  difficulties  which  may  arise  in  the  varnish  kettle 
with  regard  to  the  oil  are  attributable  to  one  of  several 
causes:  an  impure  seed,  an  improperly  manufactured  or 
prepared  oil,  immature,  or  a  product  of  too  recent  treat¬ 
ment,  any  of  which  defects  will  suffice  to  give  endless 
trouble  in  the  manipulation  of  the  ingredients. 

Linseed  oil  produced  by  the  percolation  of  benzine, 
gasoline  and  other  powerful  solvents  is  at  a  discount 
among  varnish  and  paint  manufacturers  generally.  The 
odor  of  the  solvent  clings  to  the  oil,  its  offensive  nature 
tainting  it  more  or  less,  its  removal  involving  additional 
expense.  The  same  principle  which  governs  the  removal 
of  the  chemical  traces  in  the  refining  processes  is  applic¬ 
able  here,  but  the  current  market  prices  for  linseed  oil 
are  adverse  to  such  increased  expenditure  in  the  produc¬ 
tion  of  the  naturally  odoriferous  product.  In  the  United 
States,  where  the  process  was  first  introduced  on  a  large 
scale,  the  percolation  system  is  looked  upon  with  dis¬ 
favor,  and  the  danger  to  life  and  property  involved  there¬ 
by  has  stimulated  the  legislative  bodies  of  the  majority  of 
the  respective  States  to  pass  prohibitory  laws  relative 
thereto^  which  have  the  effect  of  restricting  the  producers 
to  the  older  and  safer  system — that  of  hydraulic  pressure. 
A  few  “years  ago  an  expensively  constructed  percolator 
plant,  located  at  Toledo,  Ohio,  was  blown  to  atoms  by 
some  unfortunate  blunder.  A  naked  light  was  probably 
permitted  to  remain  in  too  close  proximity  of  the  escap¬ 
ing  fumes  of  the  volatile  fluid,  and  the  inevitable  result 
followed — the  destruction  of  property  and  loss  of  sixteen 
lives.  A  small  plant  for  the  manufacture  of  linseed  oil 
by  this  system  is  yet  in, operation  in  Ohio — the  only  one 
of  its  kind  in  the  United  States — restrictive  measures 
not  having  been  enforced  in  that  State.  Several  years  ago, 
in  Illinois,  the  writer  dismantled  a  well-equipped  plant, 


THE  MANUFACTURE  OF  LINSEED  OIL. 


23 


consisting  of  twenty-four  large  perqolators,  condensing 
tubes,  reservoirs,  and  all  the  necessary  apparatus,  includ¬ 
ing  the  expensive  and  diversified  steam  system,  the  com¬ 
bination,  which  had  only  been  in  operation  a  few  months, 
costing  nearly  |!l50,0l)0.  The  proprietors  resumed  the 
manufacture  of  linseed  oil  under  the  old  hydraulic  pres¬ 
sure  system. 

A  simple  measure  which  ensures  reliability  in  the  use 
of  a  pure  oil  consists  in  purchasing  direct  from  a  repu¬ 
table  crusher.  Having  succeeded  thus  far,  the  next  im¬ 
portant  step  in  the  evolution  of  a  superior  oil  com¬ 
patible  with  efficient  management,  is  the  degree  of  care 
which  must  be  exercised  in  the  preliminary  treatment  of 
the  product  and  in  the  various  subsequent  processes.  Oc¬ 
casionally  a  batch  of  oil  manufactured  in  the  most  ap¬ 
proved  manner  from  screened  and  well-developed  seed, 
warranted  to  have  been  submitted  to  the  usual  refining 
processes  in  the  most  skillful  manner,  and  apparently 
possessing  all  the  essential  requirements  of  a  superior 
varnish  oil,  surprises  the  operative  by  developing  features 
decidedly  repugnant  to  the  latter,  and  at  times  causing 
the  operation  to  be  brought  to  a  standstill.  Investigation 
is  set  about,  and  very  often  the  exact  origin  of  the  diffi¬ 
culty  is  involved  in  impenetrable  mystery,  all  efforts  to 
satisfactorily  solve  the  problem  being  unavailing.  In 
this  dilemma  not  infrequently  the  crusher  comes  in  for  a 
large  share  of  unmerited  abuse,  but  the  true  solution  of 
the  difficulty  may  be  traced  to  some  irregularity  of  the 
chemical  or  mechanical  treatment.  On  occasions,  how¬ 
ever,  lins.eed  oil,  made  subject  to  suitable  conditions  and 
absolutely  correct  treatment  from  a  mechanical  and 
chemical  standpoint,  and  apparently  possessing  all  the 
properties  of  a  first-class  product,  is  nothing  if  not  mys¬ 
terious  in  its  behavior  when  under  treatment  in  the  varn¬ 
ish  kettle. 


24 


THE  MANUFACTURE  OF  LINSEED  OIL. 


The  oil  which  is, absolutely  without  defect,  and  which 
may  be  appropriately  designated  the  beau  ideal  of  the 
varnish  maker,  is  manufactured  by  the  cold-pressed  sys¬ 
tem.  The  absence  of  artificial  heat  and  moisture,  to¬ 
gether  with  the  gradual  application  of  a  pressure  much 
less  than  that  which  now  obtains,  very  materially  lessens 
the  amount  of  mucilaginous  matter  which  abounds  in  the 
ordinary  oil  of  commerce  extracted  by  the  simultaneous 
action  of  heat,  moisture  and  enormous  pressure.  The 
comparatively  small  proportion  of  the  latter  found  in  an 
oil  manufactured  by  the  cold-pressed  system  is  readily 
removed.  But,  under  current  prices  of  the  raw  and  manu¬ 
factured  products,  a  brief  continuance  of  this  method  of 
manufacturing  oil  would  speedily  reduce  the  crusher  to  a 
condition  of  insolvency,  the  average  yield  varying  from 
18  to  22  per  cent,  a  very  considerable  diminution  from 
the  present  standard  of  from  30  to  35  or  36  per  cent.  The 
adequate  price  which  the  cold-pressed  oil  must  neces¬ 
sarily  command  to  ensure  reasonable  returns  to  the 
crusher  is  far  removed  from  that  entertained  or  con¬ 
sidered  commensurate  by  the  average  varnish  maker, 
however  perfect  the  product  may  be,  viewed  from  all 
standpoints;  hence  the  impracticability  of  permanently 
producing  linseed  oil  under  such  prejudicial  conditions. 
To  procure  the  full  proportion  of  extractable  oil  by  the 
hydraulic  pressure  system,  heat,  moisture,  and  pressure, 
suitably  applied  subsequent  to  fine  rolling,  become  in¬ 
dispensable  conditions. 

Owing  to  the  keen  competition  which  prevails,  the 
trend  of  the  times  is  to  produce  the  maximum  amount  of 
oil — a  circumstance  which  renders  necessary  the  adop¬ 
tion  of  extreme  measures  in  the  purification  of  the  pro¬ 
duct.  -A^s  an  additional  stimulus  to  the  crusher  in  this 
respect,  it  has  been  demonstrated  by  agricultural  chem¬ 
ists  that  the  cake  which  contains  a  proportion  of  oil  not 


THE  MANUFACTURE  OF  LINSEED  OIL, 


25 


exceeding-  7  per  cent,  is  preferable  as  a  stock  feeding 
product,  to  that  which  contains  the  greater  proportion, 
varying  from  10  to  13  per  cent. 

In  the  treatment  of  oil  intended  for  use  in  varnish¬ 
making  in  bygone  times,  the  only  requirement  con¬ 
sidered  essential  was  sufficiently  prolonged  repose  to 
effect  perfect  subsidence  of  the  suspended  impurities. 
But  under  modern  conditions  it  has  been  demonstrated 
that  subsidence  and  filtration  are  of  themselves  insuffi¬ 
cient  to  produce  an  oil  suitable  to  the  requirements  of 
varnish  making,  hence  the  introduction  of  chemical  treat¬ 
ment  of  various  forms  in  conjunction  with  the  concur¬ 
rent  action  of  mechanical  devices  to  produce  the  desired 
results.  An  oil  which  has  not  been  subjected  to  the  cus¬ 
tomary  treatment,  but  retained  for  the  purpose  of  matur¬ 
ing,  will  sometimes  develop  a  permanent  rancidity  owing 
to  the  fermentation  of  the  impurities,  thus  seriously  de¬ 
teriorating  the  quality  of  the  oil.  The  success  of  the  re¬ 
fining  processes  and  the  proportions  of  waste  are  materi¬ 
ally  influenced  b)"  the  physical  condition  of  the  oil.  The 
alkali  method  of  refining  is  much  more  wasteful  than 
that  of  sulphuric  acid.  No  known  substance — excepting 
charcoal — can  so  effectually  bleach  and  purify  linseed  oil 
as  sulphuric  acid  applied  in  a  suitable  manner.  The  sys¬ 
tem  of  percolation  by  means  of  charcoal  is,  however,  im¬ 
practicable  by  reason  of  the  great  waste  involved.  It 
may  be  further  added  that  no  known  substance  so  effectu¬ 
ally  nullifies  the  properties  essential  in  a  good  varnish  oil 
as  sulphuric  acid  injudiciously  applied.  A  comparatively 
small  proportion  of  the  acid  added  to  the  oil  in  excess  of 
the  normal  amount  will  cause  the  whole  to  vigorously 
attack  the  suspended  impurities,  their  charred  condition 
discoloring  instead  of  bleaching  the  product,  the  propor¬ 
tion  of  waste  being  exceptionally  high,  while  washing, 
however  prolonged,  will  fail  to  remove  the  traces  of  the 


26 


THE  MANUFACTURE  OF  LINSEED  OIL. 


powerful  chemical  fluid.  Although  caustic  alkali  is  some¬ 
times  used  with  good  results,  it  frequently  occurs  that  the 
prolonged  agitation  develops  an  emulsion  of  soap  and 
oil  which  render  clarification  subsequently  a  very  difficult 
matter,  the  result  being  that  the  utility  of  the  batch  of  oil 
is  seriously  jeopardized.  R.  von  Wagner  suggests  the 
use  of  zinc  chloride  instead  of  sulphuric  acid  or  caustic 
soda,  as  this  substance  clears  the  impurities  without  at¬ 
tacking  the  oil.  The  zinc  chloride  is  used  in  concen¬ 
trated  solution  of  l.(S5  specific  gravity  and  thoroughly 
agitated  with  the  oil.  After  the  chloride  solution  is  with¬ 
drawn,  the  oil  is  well  washed  with  water  and  filtered  in 
the  usual  manner.  Tannin  is  used  in  some  cases  to 
clarify  the  oil,  which  it  effects  by  coagulating  the  albu¬ 
men,  thus  facilitating  its  precipitation.  The  cheapest  and 
by  all  means  the  most  practicable  method  of  preparing 
linseed’ oil  for  use  in  varnish  making  in  large  quantities 
is  by  the  sulphuric  acid  process. 

LINSEED  OIL  REFINING  PROCESSES  ON  MANUFACTURING 

SCALE. 

A  brief  description  of  the  exact  forms  of  treatment  of 
linseed  oil  in  large  quantities,  intended  for  use  in  varn¬ 
ish  making,  as  practiced  in  the  leading  refineries  in 
Europe  and  the  United  States,  may  be  apropos  at  this 
time.  For  the  especial  method  which  we  now  purpose 
describing,  the  apparatus  brought  into  requisition  con¬ 
sists  of  two  large,  open  tanks  or  vats,  one  placed  im¬ 
mediately  beneath  the  other.  Each  tank  should  be  of  the 
capacity  of  4,500  gals.,  about,  lined  with  lead,  and  fitted 
with  a  vertical  shaft,  resting  in  a  hollow  step  on  the 
bottom  centre.  To  the  vertical  shaft  strong  wings,  or 
blades  of  common  hard  wood,  are  securely  adjusted  in  a 
horizontal  and  parallel  position.  This  constitutes  the 
agitator  or  mixer,  and  is  operated  by  steam  power,  at  a 


THE  MANUFACTURE  OF  LINSEED  OIL. 


27 


speed  not  exceeding  eighty,  and  not  less  than  sixty  revo¬ 
lutions  per  minute.  In  some  establishments  air  only  is 
used  as  a  means  of  agitating  and  mixing  the  oil  and 
acid,  a  very  excellent  product  being  the  result,  its  super¬ 
iority,  however,  being  largely  dependent  on  the  exact 
character  of  the  treatment.  The  lower  receptacle,  also 
lead-lined,  of  similar  formation  and  capacity  to  the  upper 
one,  lacks  the  interior  ecjuipment  essential  to  the  former. 
A  coil  of  lead  piping,  perforated  with  minute  holes  in  the 
upper  part,  is  spread  over  as  much  surface  of  the  bottom 
of  the  vat  as  will  uniformly  distribute  the  steam  through¬ 
out  the  oil,  the  pipe  being  closed  at  the  end.  This  has  the 
effect  of  producing  a  thorough  commingling  and  mixing 
of  the  steam  through  every  portion  of  the  mass  of  oil.  It 
is  essential  to  have  the  vats  lined  with  lead,  and  that  part 
of  the  steam  piping  which  is  below  the  surface  of  the  oil 
in  the  vat  must  also  be  of  that  metal,  owing  to  the  resis¬ 
tance  it  offers  to  the  action  of  the  sulphuric  acid.  The 
lead  pipe  is  connected  at  the  top  of  the  vat  with  ordinary 
iron  steam  piping  running  direct  to  the  boilers.  The 
upper  vat  is  filled  to  two-thirds  of  its  capacity  of  well-set¬ 
tled  and  filtered  oil.  A  solution  of  sulphuric  acid  of  66° 
Baume,  previously  prepared,  in  the  proportion  of  about 
280  tbs.  of  acid  to  100  gals,  of  cold  water,  is  now  added 
to  the  2,000  gals,  of  oil,  the  agitator  being  put  in  motion 
simultaneously.  This  has  the  effect  of  niixing  the  com¬ 
bination  in  a  most  effective  manner.  The  introduction  of 
the  chemical  solution  must  be  carefully  performed,  and 
the  agitation  continuously  maintained  for  a  period  of  five 
hours.  The  acid  attacks  the  yellowish  coloring  matter, 
producing  a  partial  saponification,  the  subsequent  pre¬ 
cipitation  of  which  has  a  decided  tendency  to  bleach 
the  oil. 

The  method  of  introducing  the  acid  into  the  oil  varies, 
and  is  carried  out  in  accordance  with  the  preconceived 


28 


THE  MANUFACTURE  OF  LINSEED  OIL. 


ideas  of  the  refiners.  For  instance,  sometimes  the  acid 
is  added  to  the  oil  in  its  full  vigor,  without  dilution  of  any 
kind,  the  chemical  action  on  the  oil  being  exactly  similar 
to  the  foregoing  method  under  normal  conditions. 

It  has  been  demonstrated,  however,  that  this  method 
of  adding  the  sulphuric  acid  in  the  preparation  of  varnish 
oil  is  defective,  by  failing  to  produce  results  of  as  satis¬ 
factory  a  nature  as  that  of  a  weaker  solution  process. 
Sulphuric  acid  is  used  in  full  strength,  and  in  much  larger 
quantities  in  the  treatment  of  refined  oil  for  use  in  white 
lead,  etc.,  etc.,  and  subjected  to  subsequent  treatment  of 
a  peculiar  nature  and  of  too  expensive  a  character  to  be 
accorded  the  ordinary  varnish  oil.  In  the  preparation  of 
the  latter,  the  weak  solution  method  is  more  suitable, 
and  should  be  selected  in  every  instance.  The  undiluted 
acid,  while  charring  the  impurities  perfectly,  that  is,  those 
impurities  with  which  it  comes  in  immediate  contact, 
fails  to  perform  the  same  function  on  the  entire  mass 
of  oil,  however  well  the  agitation  may  be  maintained, 
with  the  same  degree  of  uniformity  characteristic  of  the 
solution.  The  impurities  held  in  suspension  immediately 
beneath  the  surface  of  the  oil,  and  which  come  into 
direct  contact  wdth  the  acid  as  it  falls  from  the  carboy, 
will  first  receive  the  full  charge,  and  be  energetically 
attacked  and  transformed  into  a  charred  condition,  but 
the  subsequent  dissemination  of  the  purifying  fluid  fail¬ 
ing  to  exercise  a  similar  effect  on  the  other  portions 
of  the  oil,  a  defectively-treated  product  is  the  inevitable 
result.  Owing  to  the  increased  proportion  of  acid  and 
the  special  treatment  accorded  the  regular  refined  oil 
of  commerce,  these  objectionable  features  are  obviated. 
In  the  preparation  of  the  varnish  oil,  the  introduction  of 
the  undiluted  acid,  where  this  method  is  used,  may  be 
materially  modified  by  permitting  the  latter  to  enter  the 
oil  very  slowly,  and  in  minute  streams  from  vessels  con- 


THE  MANUFACTUl^E  OF  LINSEED  OIL. 


29 


taining  the  purifying  liquid,  placed  at  even  distances 
apart  over  the  oil’s  surface,  but  by  whatever  means  ap¬ 
plied,  the  results  are  inferior  to  that  of  the  solution 
system. 

At  the  expiration  of  the  specified  time  allotted  for 
mixing  the  contents  of  the  upper  vat,  the  mixture  is 
caused  to  run  into  the  lower  or  steaming  vat.  The 
perforations  in  the  lead  pipe  coil  spread  over  the  bot¬ 
tom  of  the  vat  enable  the  escaping  steam  to  be  not 
only  uniformly  distributed  throughout  the  oil,  but  to 
enter  the  latter  with  great  force;  thus  facilitating  the 
continuous  changing  of  position  of  the  treated  oil,  and 
bringing  the  steam  into  direct  contact  with  its  every  por¬ 
tion. 

The  object  in  this  steaming  or  washing  process  is  akin 
to  that  practiced  in  the  refining  of  petroleum,  which  is 
the  eradication  of  all  traces  of  the  purifying  factor. 

Subsequent  to  the  washing  process,  and  during  the 
settling  period,  the  condensed  steam  in  the  form  of  water 
facilitates  the  precipitation  of  the  acid  previously  dissemi¬ 
nated  throughout  the  oil.  The  steaming  operation  is 
maintained  for  a  longer  or  shorter  period  in  harmony 
with  the  established  views  of  the  refiner.  Six  hours  is 
the  standard  time  in  some  refineries,  while  others  vary 
the  continuance  of  the  operation  very  considerably  in 
periods  ranging  from  six  to  forty  hours. 

At  the  termination  of  the  steaming  process,  the  oil 
should  be  permitted  undisturbed  rest  for  at  least  forty- 
eight  hours,  during  which  the  subsidence  of  all  matter 
present  in  the  oil  will  have  been  materially  effected — 
water,  sulphuric  acid,  and  extraneous  matter — while  a 
clarified  and  well  bleached  product  will  float  over  all. 
I'he  oil  is  permitted  to  remain  in  the  treating  tank  in 
many  cases  for  a  more  extended  period,  not  infrequently 
a  week  or  more,  to  still  further  facilitate  the  precipitation 


30 


THE  MANUFACTURE  OF  LINSEED  OIL. 


of  suspended  matter,  after  which  the  water  is  drawn  off, 
and  the  following  day  the  oil  is  pumped  into  temporary 
storage  tanks,  whence  it  is  again  withdrawn  to  be 
passed  through  the  filter  press,  subsequent  to  which  pro¬ 
cess  it  is  finally  pumped  into  permanent  storage  tanks 
for  further  settling  and  maturing  prior  to  use. 

As  an  additional  precautionary  measure  to  effect  the 
complete  removal  of  moisture  which  may  yet  remain 
in  the  oil,  subsequent  to  the  steaming  operation,  the 
latter  is  sometimes  submitted  to  a  heating  or  drying 
process  in  a  steam-jacketed  kettle  prior  to  filtration,  and 
for  a  space  of  four  or  five  hours  maintained  at  a  point 
in  temperature  below  that  which  produces  discoloration. 
By  this  means  every  vestige  of  moisture  is  driven  off  and 
the  oil  is  very  materially  improved  thereby.  The  steam- 
jacketed  drying  kettle  should  be  equipped  with  an  agi¬ 
tator  to  diffuse  the  heat  throughout  the  oil. 

Another  process  equally  efficient  consists  in  using  air 
as  an  agitating  and  oxidizing  factor,  coincident  with  the 
uniform  distribution  of  the  sulphuric  acid  added  to  the 
oil  in  the  upper  vat,  instead  of  by  mechanical  agitation 
as  described.  The  results  chemically  are  similar,  al¬ 
though  there  are  refiners  who  maintain  that  the  latter 
process  is  the  more  effective  in  producing  a  satisfactory 
product. 

A  process  of  preparing  linseed  oil  by  bleaching  and 
purifying  through  the  aid  of  hydrate  of  alumina  has 
established  for  itself  a  high  reputation  among  consumers 
of  refined,  or  varnish  oils.  In  the  treatment  of  linseed 
oil,  hydrate  of  alumina  as  a  purifying  and  bleaching  factor 
possesses  advantages  over  other  substances  peculiar  to 
itself.  Oil  treated  with  this  product  is  less  liquefied  or, 
in  other  words,  possesses  more  “body”  than  that  which  is 
treated  by  the  sulphuric  acid  process.  The  latter,  while 
a  superior  bleaching  and  purifying  agent,  used  in  normal 


THE  MANUFACTURE  OF  LINSEED  OIL. 


31 


proportions  and  under  suitable  conditions,  displays  a 
marked  tendency  to  reduce  the  specific  gravity  of  the 
oil,  the  interpretation  of  which  means,  a  greater  or  less 
liquefied  condition  and  proportional  decrease  in  flowing 
property  and  “body,”  most  undesirable  features  in  var¬ 
nish.  These  are  the  chief  objections  to  the  use  of  sul¬ 
phuric  acid,  while  the  principal,  if  not  the  only  objection 
to  the  use  of  hydrate  of  alumina,  consists  in  the  abnormal 
proportion  of  waste  unavoidable  in  its  use.  However, 
where  circumstances  warrant  the  use  of  the  latter — the 
consumer  requiring  a  very  superior  oil  and  paying  a 
commensurate  price  therefor — hydrate  of  alumina  is 
brought  into  requisition  among  progressive  varnish 
makers.  As  the  waste  referred  to  renders  the  general 
use  of  this  system  impracticable,  we  deem  it  scarcely  nec¬ 
essary  to  give  further  particulars  of  the  process. 

There  are  a  surprising  number  of  materials  of  a  nat¬ 
ural  or  chemical  composition,  which,  if  applied  to  linseed 
oil  in  a  suitable  manner,  will  remove  the  jellified  or 
gelatinous  substance  which  becomes  apparent  when  raw 
or  improperly  treated  oil  is  submitted  to  the  action  of  a 
high  temperature.  Ground  lime,  fuller’s  earth  in 
powdered  form,  zinc  oxide,  yellow  ochre,  alkali  and  very 
many  other  substances,  when  treated  with  linseed  oil, 
produce  bleaching  properties  coincident  with  the  exercise 
of  their  cleansing  or  purifying  powers. 

The  writer  has  obtained  excellent  results  by  treating 
raw  linseed  wdth  fuller’s  earth  with  filtration  as  a  final 
process.  The  drawback  to  this  mode  of  treatment  con¬ 
sists  in  waste,  caused  by  the  absorption  of  the  oil  by 
the  fuller’s  earth,  the  recovery  of  which  would  prove  an 
expensive  matter.  In  Germany,  France  and  the  United 
States,  this  system  of  refining  is  regularly  operated, 
though  on  a  somewhat  limited  scale,  the  residue  of  waste 
being  used  for  certain  classes  of  paint.  Doubtless  if  a 


32 


THE  MANUFACTURE  OF  LINSEED  OIL. 


sufficient  demand  arose  at  remunerative  figures  for  this 
variety  of  paint  ingredient  the  adoption  of  the  fuller’s 
earth  system  of  purifying  and  bleaching  linseed  oil  would 
become  much  more  general. 

Refined  cottonseed  oil — the  yellow  variety — is  treated 
with  fuller’s  earth  for  the  purpose  of  producing  a  water- 
white  aspect,  and  which  product  is  known  commercially 
as  “Winter  or  Summer  White.”  Similar  treatment  will 
not  only  bleach  linseed  oil,  but  will  effectually  remove 
the  gelatinous  substance  previously  referred  to  and  pur¬ 
ify  it  in  a  very  efficient  manner.  Experiments  are  be¬ 
ing  constantly  made  by  practical  cottonseed  oil  refiners 
to  obviate  the  great  waste  the  use  of  fuller’s  earth  en¬ 
tails,  but  so  far  without  substantial  results.  To  this 
fact  is  owing  the  relatively  high  price  at  which  the 
“W^inter  White”  variety  of  cottonseed  oil  is  sold. 


fuller’s  earth  as  a  refining  agent. 

In  the  treatment  of  linseed  oil  a  small  percentage  of 
fuller’s  earth  is  mixed  with  the  oil  and  briskly  agitated 
for  three  or  four  hours,  and  succeeded  by  slow  filtration 
to  remove  the  impurities  and  fuller’s  earth.  Concur¬ 
rently  with  the  former  operation,  which  is  sometimes 
accomplished  in  a  steam-heated  kettle,  the  mixture  is 
submitted  to  a  temperature  of  about  200°  Fahr.  for  the 
space  of  one  hour.  This  has  the  effect  of  bringing  into 
operation  the  properties  of  the  earthy  substances,  which 
bear  a  close  resemblance  to  those  of  known  alkaline 
composition,  which  are  valuable  purifying  and  bleaching 
agents,  but,  unfortunately,  productive  of  anomalous 
waste. 

The  best  quality  of  fuller’s  earth  contains  but  little 
calcium  or  lime.  The  average  analysis  contains: — 


THE  MANUFACTURE  OF  LINSEED  OIL. 


33 


65  per  cent  silica. 

20  “  alumina. 

9  “  iron. 

6  “  lime. 

100 

The  component  constituents  of  the  product  may  vary 
considerably.  Linseed  oil  improperly  treated  with  ful¬ 
ler’s  earth  will  sometimes  show  a  greenish  tinge.  The 
writer  has  recently  experimented  successfully  with  ful¬ 
ler’s  earth  in  linseed  oil  refining,  by  demonstrating  that 
a  well-bleached  oil  may  be  prepared  by  its  use,  together 
with  the  complete  removal  of  the  undesirable  gelatinous 
matter.  The  absence  of  the  latter  became  apparent  on 
submitting  a  sample  of  the  treated  oil  to  a  temperature 
of  550°  Fahrenheit,  thus  producing  a  very  superior  var¬ 
nish  oil. 

Ground  glass  and  fuller’s  earth  intimately  associated 
are  sometimes  used  to  effect  the  same  object,  the  pro¬ 
portions  of  the  earth  being  equivalent  to  three  parts  to 
one  of  ground  glass. 

The  use  of  ground  lime  as  a  purifying  agent  in  lin¬ 
seed  oil,  in  conjunction  with  zinc  chloride,  displays  a 
wasteful  saponification,  even  if  used  in  very  small  pro¬ 
portions,  a  circumstance  which  renders  its  use  imprac¬ 
ticable.  A  small  sample  examined  several  days  after 
treatment  showed  a  heavy  percentage  of  loss,  the  sub¬ 
sided  matter  very  much  resembling  a  mass  of  animal 
grease. 

To  still  further  bleach  an  oil  which  has  been  already 
submitted  to  any  of  the  foregoing  treatments,  and  by 
lessening  the  yellowish  shade  and  producing  an  almost 
water-white  oil,  solar  light  exerts  a  salient  influence. 
Probably  the  very  best  oil — that  which  commends  it¬ 
self  to  the  consideration  of  the  varnish  maker  to  a 


34 


THE  MANUFACTURE  OF  LINSEED  OIL. 


greater  degree  than  any  other  prepared  oil — is  that  which 
has  been  subjected  to  the  action  of  solar  light  for  a 
suitable  period.  As  an  essential  part  of  the  refining 
process,  this  principle  demands  consideration,  and  in 
the  refineries  noted  for  their  uniform  output  of  well- 
bleached  and  refined  oil  the  system  is  maintained  per¬ 
manently.  In  the  establishment  referred  to,  it  is  carried 
on  as  a  supplemental  or  auxiliary  process  to  the  fore¬ 
going  methods  of  treatment,  the  final  one  being,  how¬ 
ever,  that  of  filtration.  It  is  most  important  that  as  large 
a  surface  of  the  oil  as  circumstances  will  permit  should 
be  exposed  to  the  solar  influence.  By  presenting  an 
extended  surface  area  of  the  oil  and  in  shallow  vessels, 
the  solar  rays  effectively  penetrate  the  fluid,  and  are 
materially  facilitated  in  the  bleaching  functions  they  are 
expected  to  perform. 

A  depth  of  about  one  foot  should  not  be  exceeded  in 
the  bleaching  tanks.  While  it  is  incontrovertible  that  the 
sun’s  chemical  influence  as  an  oil  bleacher  is  of  the 
highest  order,  it  has  also  been  ascertained  that  by  ex¬ 
posing  a  very  shallow  proportion  of  oil — say  four  or  five 
inches — to  long-continued  solar  action,  the  heat  radiat¬ 
ing  from  the  latter  tends  to  fasten  the  yellow  coloring 
matter  in  the  oil  instead  of  eliminating  it.  To  avoid  the 
deleterious  consequences  resulting  from  either  extreme, 
a  depth  of  oil  not  less  than  nine  inches  and  not  more 
than  twelve  inches  should  be  carried  in  the  bleaching 
tanks. 

FORM  OF  TREATING  TANKS  AND  REFINING  EQUIPMENT. 

A  modern  refinery  consists  in  having  a  series  of 
large,  square  tanks — probably  twenty  feet  square  and 
about  fourteen  inches  in  depth — especially  constructed 
for  bleaching  the  oil,  and  in  addition  to  the  regular 


THE  MANUFACTURE  OF  LINSEED  OIL. 


35 


treating  vats  or  tanks.  The  bleaching  tanks  are  some¬ 
times  copper-lined  and  in  every  instance  should  be  sit¬ 
uated  immediately  beneath  a  large  glass  roof,  so  that 
the  direct  rays  of  light  will  fall  upon  the  entire  surface 
uninterruptedly.  The  oil  is  allowed  to  remain  in  the 
square  tanks  several  weeks,  after  which  period  it  should 
be  slowly  passed  through  the  filter  press,  when  it  will 
be  found  a  very  superior  oil,  suitable  for  the  finest  variety 
of  varnish,  shall  have  been  obtained. 

Tn  Europe,  linseed  oil  is  not  infrequently  prepared 
for  use  in  varnish  making  by  this  simple  treatment 
only,  the  preliminary  and  subsequent  conditions  being 
a  well-settled  and  thoroughly  filtered  oil,  respectively. 

A  method  of  bleaching  oil  is  practiced  in  Ger¬ 
many,  having  in  view  that  of  solar  light,  by  means  of 
which,  it  is  asserted,  a  thoroughly  bleached  oil  is  reg¬ 
ularly  obtained,  without  recourse  to  other  bleaching 
agents.  It  is  well  known  that  raw  linseed  oil,  like  other 
vegetable  products  of  a  like  nature,  if  sufficiently  long 
exposed,  may  be  bleached  by  the  action  of  solar  light 
alone,  but  the  length  of  time  expedient  to  effect  the  de¬ 
sired  object  renders  the  adoption  of  this  slow  system, 
for  commercial  purposes,  highly  impracticable.  The  ex¬ 
posure  of  a  small  sample  of  oil  in  the  most  prominent 
position  to  the  full  radiance  of  the  daylight,  will  probably 
require  six  months  or  more  to  lighten  the  natural 
yellow  color  which  is  characteristic  of  linseed  oil,  while 
the  advantages  derived  from  the  German  system  referred 
to,  and  which  will  hereafter  be  described,  consists  in  the 
fact  that  a  well-bleached  product  may  be  obtained  in  as 
many  weeks. 

By  the  aid  of  powerful  reflectors  the  solar  light  is 
intensified  and  reflected  with  accumulated  force  on  the 
surface  of  the  oil  in  shallow  tanks,  similar  to  those  pre¬ 
viously  described.  The  bottom  of  the  tank  is  some- 


36 


THE  MANUFACTURE  OF  LINSEED  OIL. 


times  utilized  by  transforming  it  into  a  powerful  reflector 
also,  thus  materially  facilitating  the  bleaching  process. 
It  is  alleged  that  better  results  are  procured  by  this 
unique  method  of  bleaching  linseed  oil  than  those  of  any 
other.  But  while  a  bleached  oil  may  be  obtained  in  this 
manner,  it  is  diflflcult  to  comprehend  how  such  a  pro¬ 
duct  from  which  the  gelatinous  substance  has  not  been 
eliminated,  and  which  therefore  must  be  pronounced  an 
inferior  varnish  oil,  can  equal  from  any  standpoint — ex¬ 
cepting  perhaps  that  of  color — an  oil  prepared  by  acid 
treatment  and  which  is  absolutely  freed  from  the  deleter¬ 
ious  matter  referred  to.  A  combination  of  the  processes, 
each  being  a  complemental  essential  in  the  general 
treatment  of  the  oil,  would  seem  to  be  the  most  feasible 
course  to  pursue  in  the  production  of  a^  superior  var¬ 
nish  oil.  It  is'  recognized  that  however  long  an  oil  may 
be  permitted  to  settle,  or  to  whatever  mechanical 
treatment  it  may  have  been  subjected,  the  complete 
eradication  of  the  gelatinous  substance  which  becomes 
apparent  when  raw  oil  is  submitted  to  a  high  tempera¬ 
ture,  cannot  be  effected  without  a  material  chemical 
treatment. 

Several  years  ago,  in  Chicago,  the  writer  received  a 
trade  circular,  a  copy  of  which  was  distributed  among 
varnish  men  and  paint  manufacturers  generally,  an¬ 
nouncing  the  fact  (?)  that  a  refined  or  varnish  oil  was 
placed  on  the  market  treated  by  mechanical  means  only, 
and  which  was  guaranteed  to  equal  in  working  prop¬ 
erties  refined,  or  varnish  oil,  prepared  by  the  combination 
of  mechanical  and  chemical  processes.  Special  stress 
was  impressed  on  the  trades,  especially  white  lead  man¬ 
ufacturers,  that  the  absence  of  acid  traces  in  the  oil 
rendered  its  use  in  grinding  absolutely  without  defect, 
while  for  varnish  making  it  was  also  stated  it  was  super¬ 
ior  to  anything  previously  introduced.  But  upon  being 


THE  MANUFACTURE  OF  LINSEED  OIL. 


37 


put  to  the  practical  test,  while  its  aspect  appeared  fault¬ 
less,  the  product  was  found  lacking  the  essential  re¬ 
quirements  of  varnish  making  and  its  ephemeral  exist¬ 
ence  was  speedily  relegated  among  the  things  of  the  past. 

It  is  a  comparatively  safe  assumption  to  state  that  for 
ordinary  commercial  purposes  all  refined  linseed  oil  is 
prepared  by  the  sulphuric  acid  process.  The  practica¬ 
bility  of  treating  large  quantities  of  oil  at  a  single  opera¬ 
tion  renders  its  use  most  economical,  as  compared  with 
other  methods. 

Probably  the  very  best  bleached  oil — that  which  is 
water-white — is  obtained  by  filtration  through  charcoal 
or  animal  black;  but  the  great  waste  involved,  together 
with  the  tediousness  of  the  filtering  operation,  are  insur¬ 
mountable  difficulties  in  the  way  of  its  general  adoption. 
From  40  to  50  per  cent  of  waste  is  incurred,  while  the 
minute  stream  of  oil  which  percolates  through  the  filter¬ 
ing  medium  at  the  commencement  of  the  operation, 
gradually  decreases  until  drops  descend  with  slowly-in¬ 
creased  intervals  between  each,  circumstances  which  un¬ 
mistakably  point  to  the  fact  that  the  material  is  becoming 
rapidly  gummed  up — another  objectionable  feature  char¬ 
acteristic  of  charcoal  and  animal  black. 

In  all  methods  of  oil  bleaching,  none  can  produce  an 
absolutely  pure  water-white  oil — the  charcoal  process 
alone  excepted.  A  slight  yellow  or  greenish  shade  will 
be  perceptible  in  a  sample  selected  from  the  best 
variety  on  the  market.  Nevertheless,  within  the  past 
two  years  a  refined  oil  has  been  introduced  in  the 
United  States  which  has  attracted  very  considerable  at¬ 
tention  among  varnish  men,  owing  to  the  fact  that  it 
closely  approaches  the  standard  as  set  by  the  charcoal 
process,  viewed  from  a  color  standpoint,  while  its  action 
under  treatment  in  the  varnish  kettle  is  all  that  need  be 
desired.  The  process  is  patented  in  England  as  well  as 


38 


THE  MANUFACTURE  OF  LINSEED  OIL. 


in  the  United  States,  and  a  brief  description  of  its  main 
features  may  prove  interesting. 

VEGETABLE  OIL  REFINING  BY  MEANS  OF  THE  OCHRE 

PROCESS, 

The  patentee  claims  for  his  invention  an  improved 
method  of  refining  cottonseed  oil,  linseed  and  analogous 
oils,  rendering  same  of  very  superior  quality.  The  pro¬ 
cess  is  carried  out  by  the  use  of  hematite  or  limonite,  or 
any  similar  substance  of  the  nature  of  a  pigment,  which 
does  not  injure  the  oil  as  an  article  of  food,  as  in  the 
case  of  edible  cottonseed  oil.  By  mixing  and  agitating 
the  previously  prepared  ochre,  in  certain  proportions, 
with  the  oil  to  be  refined,  the  gum,  resin  and  coloring 
matter  contained  in  the  oil  are  taken  up  and  separated 
from  the  oil,  thus  purifying  and  refining  it.  In  the  prac¬ 
tice  of  the  invention,  the  patentee  further  states  that  the 
ochres  may  be  employed  alone  as  the  refining  agent,  or 
in  connection  with  other  materials,  by  mixing  thoroughly 
with  the  ochre  and  treating  the  oil  therewith,  or  by  em¬ 
ploying  such  materials  as  a  preliminary  or  subsequent 
treating  agent,  before  or  after  the  oil  has  been  treated 
with  the  ochre.  The  ochre  is  prepared  by  removing  all 
uncombined  water  by  the  application  of  heat,  the  latter 
maintained  until  an  orange  color  is  assumed.  In  the 
use  of  umber  and  siennas,  the  heat  is  continued  until 
the  former  becomes  a  deep  brown,  and  the  latter  a 
light  red  color. 

In  some  instances  the  ochre  is  dried  and  pulverized 
to  fineness,  and  used  in  from  four  to  twelve  parts  of 
oil  to  one  part  of  ochre,  according  to  the  amount  of 
impurities  the  oil  contains.  The  combined  oil  and  ochre 
is  then  briskly  agitated  for  forty  minutes,  and  as  soon 
as  the  combination  has  been  sufficiently  agitated  and  the 
refining  completed,  the  oil  is  separated  from  the  ochre, 


THE  MANUFACTURE  OF  LINSEED  OIL. 


39 


by  the  use  of  the  filter  press,  or  left  to  settle  twenty-four 
hours,  and  then  drawn  ofif,  leaving  only  the  residuum 
to  be  filtered,  which,  as  it  comes  from  the  press,  is  a 
stiff  paste  of  ochre,  oil  and  its  impurities  in  the  form  of 
a  cake. 

Furthermore,  the  inventor  directs,  that  in  some  classes 
of  oil,  which  has  undergone  more  or  less  change  by 
taking  oxygen,  and  is  heavily  charged  with  the  free  fatty 
acids  and  other  impurities,  the  ochre  is  reduced  to  a  fine 
powder  from  which  ten  per  cent  of  the  amount  to  be 
used  is  taken,  and  associated  with  from  one-half  per  cent 
to  one  and  one-half  per  cent  of  the  oil,  dry  caustic  soda, 
or  biborate  of  soda  (borax)  in  a  finely  powdered  state. 
The  combination  is  mixed  with  the  oil  to  be  refined 
and  agitated  briskly  for  from  ten  to  fifteen  minutes. 
Twice  the  weight  of  soda,  or  of  chloride  of  calcium 
is  then  added,  in  just  enough  water  to  dissolve  it,  the 
agitation  being  continued  for  from  ten  to  fifteen  minutes 
longer.  The  balance  of  the  ochre,  necessary  to  complete 
the  refining,  is  now  added,  agitation  is  resumed  for  a 
short  period  (about  ten  or  fifteen  minutes),  the  temper¬ 
ature  of  the  oil  being  maintained  at  summer  heat.  The 
oil  is  then  filtered.  In  the  latter  process  the  drying 
operation,  with  regard  to  the  ochre,  may  be  omitted. 

The  waste  unavoidable  in  this  process,  or  processes, 
necessarily  increases  the  cost  of  the  prepared  oil.  The 
proportion  of  oil  which  remains  in  the  ochre,  after  the 
latter  has  been  utilized  as  the  refining  agent,  is  probably 
the  chief  objection  to  its  use.  The  suggestion  that  the 
oil-saturated  ochre  might  be  utilized  as  a  low  grade  paint, 
might  be  brought  into  operation  for  a  short  time,  and 
thus,  to  a  certain  extent,  recover  the  waste  product,  but 
the  supply  would  so  far  over-reach  the  demand  that  the 
inevitable  glut  would  accumulate  instead  of  being  appre¬ 
ciably  relieved. 


40 


THE  MANUFACTURE  OF  LINSEED  OIL. 


In  the. use  of  fuller’s  earth  the  same  difficulty  arises, 
and  the  inventor  who  devises  an  economical  method  of 
recovering  the  oil  absorbed  by  such  materials  will  have 
accomplished  a  most  progressive  step  in  the'  art  of  oil 
refining.  From  four  to  twelve  per  cent  of  oil  is  lost  in 
the  treatment  of  the  various  vegetable  oils  by  the  use  of 
the  foregoing  materials.  The  application  of  steam  to  the 
residuum  will  effectually  remove  the  oil,  but  the  labor 
involved  in  thoroughly  saturating  the  mass  with  steam 
and  cost  of  separation  of  the  oil  from  the  water  sub¬ 
sequently,  will  aggregate  more  than  the  original  waste 
loss. 

The  patented  ochre  process  is  sometimes  applied,  as 
in  the  case  of  fuller’s  earth,  to  an  oil  already  treated  by 
the  sulphuric  acid  process,  the  result  proving  the  nearest 
approach  to  water-white  linseed  oil  which  science  has  so 
far  rendered  possible. 

In  pursuit  of  a  cheaper  substance  which  might  serve 
the  same  purpose  as  ochre  or  fuller’s  earth,  the  writer 
recently  experimented  with  sand  ground  to  an  impalpable 
powder,  but  the  result,  as  was  to  be  expected,  proved 
that  the  fine  silicious  particles,  lacking  the  calcium  or 
lime  ingredients  in  their  composition,  remained  uncom¬ 
bined  with  the  impurities,  however  persistently  the  agita¬ 
tion  was  maintained,  and  in  subsidizing,  when  the  whole 
was  in  a  state  of  repose,  failed  to  hasten  the  precipitation 
of  any  extraneous  matter.  By  filtering  a  cloudy  oil 
through  sand,  while  the  natural  color  will  remain  un¬ 
changed,  it  may  be  rendered  bright. 


Press  Room  Operations  and  Their  Effect  Upon  the  Oil  in  Re¬ 
fining— Method  of  Testing  of  a  Varnish  Oil. 


It  has  been  demonstrated  that  a  heavy  percentage  of 
waste  is  unavoidably  present  in  refining  an  oil  which  has 
been  obtained  by  fine  rolling  and  the  continuity  of  the 
maximum  pressure  for  a  comparatively  protracted 
period.  The  minute  specks,  and  at  times  flocculent  mat¬ 
ter,  which  appears  suspended  in  the  oil,  subsequent  to 
the  application  of  the  fire  test,  will  not  freely  precipitate, 
although  in  the  first  instance  the  crude  oil  may  have  been 
subjected  to  the  regular  treatment,  and  in  an  efficient 
manner.  It  may  happen  that  this  drawback  confronts 
the  operator  at  a  time  when  the  product  under  treat¬ 
ment  is  intended  for  immediate  use.  This  defect  is  not 
palpable  until  the  expiration  of  a  certain  period  subse¬ 
quent  to  the  washing  process,  and  if  time  were  of  no 
particular  consequence  the  difficulty  could  be  obviated 
by  prolonged  settling.  To  procure  a  faultless  oil  within 
the  prescribed  limitations,  it  therefore  becomes  essential 
to  resort  to  a  supplementary  process.  In  addition  to  the 
surplus  waste,  characteristic  of  the  treatment  of  such  a 
product  in  the  first  instance,  that  which  is  obtained  by  the 
secondary  process  augments  the  already  abnormal  pro¬ 
portion  in  the  same  ratio. 

Oil  extracted  from  the  crushed  and  cooked  seed  under 
less  exacting  conditions  is  much  more  susceptible  of 
treatment,  and  presents  a  proportional  diminution  in 
waste.  To  successfully  meet  this  contingency  not  a 
few  of  the  leading  crushers  in  England  and  the  United 
States,  while  manufacturing  linseed  oil  on  a  large  scale 
under  the  most  approved  conditions,  for  the  extraction 
of  the  obtainable  oil,  at  stated  times  operate  a  portion 
of  the  mill  in  the  manufacture  of  an  oil  especially  in- 

41 


42 


THE  MANUFACTURE  OF  LINSEED  OIL. 


tended  for  this  trade,  obtained  under  comparatively  light 
pressure  and  for  which  a  price  is  procured  commensu¬ 
rate  with  the  cost  of  production.  Not  infrequently  the 
cake  from  which  this  oil  has  been  pressed,  and  which  nat¬ 
urally  contains  a  heavy  percentage  of  oil,  is  ground  fine 
and  slowly  added  to  the  material  in  the  press  room, 
kettle  or  heater,  and  the  surplus  oil  recovered  in  the 
regular  manner. 

In  the  production  of  a  superior  varnish,  it  is  essential 
that  the  oil  possess  no  defective  properties;  but  for  the 
manifold  uses  to  which  linseed  oil  is  subjected  in  the 
various  industrial  arts,  a  well  settled  oil  made  under  any 
conditions,  from  an  ordinary  quality  of  seed,  is  usually 
suitable  for  all  requirements.  Refined  linseed  oil 
intended  for  use  in  white  lead  grinding  must,  however, 
possess  very  superior  qualities,  and  the  care  essential  in 
the  removal  of  acid  traces  in  the  washing  operation 
must  be  on  a  par  with  that  intended  for  use  in  the 
manufacture  of  superior  varnishes. 

To  determine  the  real  value  of  an  oil  as  a  varnish 
ingredient,  by  ascertaining  its  exact  physical  properties 
and  general  conduct  in  the  treating  kettle,  together  with 
the  proportion  of  waste  as  a  result  of  destructive  distilla¬ 
tion  of  escaping  vapors,  the  following  method  should 
be  adopted,  and  may  be  looked  upon  as  a  positively  accu¬ 
rate  'guide. 

From  the  tank  in  which  oil  is  temporarily  stored,  take 
say  fifteen  pounds  of  the  fluid  and  pour  into  a  small 
copper  pot.  The  latter  should  be  weighed  previously,  so 
that  in  addition  to  its  actual  weight,  fifteen  net  pounds 
of  oil  will  be  ready  for  treatment.  With  a  suitable  lid 
adjusted,  having  an  opening  sufficiently  large  to  permit 
the  entry  of  a  four  or  six-inch  pipe,  the  pungent  vapors 
arising  from  the  heated  oil  may  be  conveyed  to  the 
nearest  chimney.  The  use  of  a  good  draught  of  air  in 


THE  MANUFACTURE  OF  LINSEED  OIL. 


43 


the  furtherance  of  this  object  is  a  most  desirable  matter. 
The  draught  pipe  is  indispensable  if  the  operation  is  to 
be  carried  out  under  cover.  A  movable  segment  of  the 
lid  opening  on  hinges  permits  the  stirrer,  or  paddle,  to 
move  freely  through  the  oil,  while  it  also  facilitates  close 
inspection  of  the  fluid  throughout  the  entire  testing  oper¬ 
ation.  The  exact  principles  which  govern  the  manufac¬ 
ture  of  lithographic  printing  ink  in  its  incipient  stages 
are  now  brought  into  requisition.  But,  instead  of  per¬ 
mitting  the  surface  of  the  oil  in  the  copper  pot  to  remain 
uncovered  and  in  conflagration,  as  in  the  case  of  prepar¬ 
ing  oil  for  printing  ink,  the  lid  and  draught  pipe  are  used. 
The  Are  should  be  composed  of  coke,  or  wood  chemically 
treated,  and  a  uniform  heat  maintained  as  far  as  pos¬ 
sible.  The  thermometer,  which  should  pass  through  an 
opening  in  the  lid,  should  remain  suspended  in  the  oil, 
about  one  inch  from  the  bottom  of  the  pot,  and  when 
500°  Fahrenheit  is  recorded  the  testing  operation  has 
actually  commenced.  By  closely  observing  the  action  of 
the  oil  in  the  pot  as  the  process  advances,  the  varnish 
maker  may  acquire  a  knowledge  of  a  definite  character 
concerning  its  behavior  when  in  greater  volume  subse¬ 
quently  in  the  varnish  kettle,  and  thus  fortified,  his  pro¬ 
cedure  is  guided  with  a  precision  otherwise  unattainable. 
The  temperature  mentioned  should  be  maintained  unre¬ 
laxed  from  two  and  one-half  to  three  hours,  according  to 
the  nature  of  the  oils.  The  indications  which  point  to 
the  approaching  termination  of  the  process  may  be  ascer¬ 
tained  by  withdrawing  a  small  quantity  of  the  oil  on 
knife,  or  paddle,  and  when  cool  apply  the  finger,  to 
whicli  it  adheres.  Its  adhesiveness  will  permit  it  to  be 
drawn  out  to  a  considerable  length  before  separating. 
The  paddle  should  be  continuously  operated  throughout 
the  process  to  promote  a  uniform  dissemination  of  heat 
in  the  oil,  and  until  the  desired  consistency  has  been  pro- 


44 


THE  MANUFACTURE  OF  LINSEED  OIL- 


cured.  The  pot  is  withdrawn  from  the  fire  at  the  suitable 
moment,  and  with  its  contents  carefully  weighed,  the 
proportion  of  weight  lacking  the  original  amount  being 
the  exact  percentage  of  loss.  From  ten  to  twelve  per 
cent  loss  indicates  that  the  oil  may  be  treated  econom¬ 
ically,  while  a  greater  proportion  will  in  the  same  ratio 
present  a  heavier  waste  when  submitted  to  treatment 
in  the  varnish  kettle.  In  this  system  it  will  be  demon¬ 
strated  that  the  oil  which  reveals  the  minimum  of  waste 
is  that  which  best  receives  the  heat,  and  therefore 
cooks  rapidly  and  most  satisfactorily.*  An  impure  oil 
proves  troublesome  in  cooking  and  wasteful  to  a  degree. 

While  the  results  shown  may  not  be  accepted  as  an 
exact  criterion  of  those  which  characterize  the  manipula¬ 
tion  of  a  large  batch  of  varnish,  the  maximum  degree 
of  temperature  on  the  latter  being  rarely  maintained  for 
more  than  one  hour,  or  two-thirds  less  time  than  that 
occupied  by  the  test,  it  accurately  serves  to  disclose  the 
nature  and  peculiar  features  of  the  product  prior  to  being 
subject  to  the  influence  of  the  intense  heat  on  a  much 
larger  scale  in  the  varnish  kettle.  While  oil  in  the  var¬ 
nish  kettle  is  exposed  to  the  action  of  intense  heat  for  a 
much  less  duration  of  time,  a  greater  proportion  of 
vapors  is  evolved  by  reason  of  the  fact  that  large  bodies 
of  oil  retain  heat  longer  than  when  treated  on  a  small 
scale,  the  continuation  of  the  heat  being  synonymous 
with  that  of  waste;  but  the  waste  caused  by  treatment  of 
a  batch  of  oil  in  the  varnish  kettle  may  be  approxi¬ 
mately  estimated  beforehand  by  the  method  just  de¬ 
scribed. 

When  the  oil  thus  treated  in  the  small  copper  pot  has 
been  allowed  sufficient  time  to  cool,  it  will  assume  a 
rubber-like  consistency.  The  greasy  condition  character¬ 
istic  of  fixed  oils  will  have  disappeared,  and  from  an 


THE  MANUFACTURE  OF  LINSEED  OIL. 


45 


industrial  standpoint  the  product  is  of  no  further  practical 
value. 

By  being  suitably  applied  to  a  surface  it  may,  how¬ 
ever,  be  used  to  excellent  advantage  in  the  extermina¬ 
tion  of  vermin.  Its  adhesiveness  to  the  pedal  extremities 
of  such  pests  being  greater  than  their  limited  strength 
can  overcome,  and  in  this  helpless  condition  they  are 
speedily  despatched. 

The  radical  changes  which  have  been  effected  in  mod¬ 
ern  oil  milling  machinery,  and  methods  in  design  and 
principle  respectively,  have  materially  changed  the  condi¬ 
tions  which  formerly  confronted  the  varnish  maker.  Ow¬ 
ing  to  the  primitive  character  of  the  old  mechanical 
appliances,  the  possibility  of  a  thorough  extraction  of  the 
oil  from  the  seed  was  precluded,  a  circumstance  which  ob¬ 
viated  the  presence  of  such  a  large  proportion  of  gummy 
matter  as  is  present  in  the  crude  oil  as  made  to-day,  even 
under  the  most  favoring  conditions.  The  prolonged 
settling  allowed  an  oil  intended  for  varnish  purposes,  to¬ 
gether  with  the  protracted  period  invariably  extended  to 
the  varnish  itself,  gave  the  refiners  and  varnish  makers 
of  the  last  generation  advantages  of  a  very  superior 
order.  But  the  modern  consumption  of  varnish  is  in¬ 
creasing,  having  almost  immeasurably  outgrown  the 
proportions  of  former  days,  while  the  popular  taste  for 
artistic  work,  in  which  this  commodity  takes  such  a 
primary  part,  correspondingly  augments  the  demand. 
The  long  preliminary  oil  settling  is  inconvenient,  if  not 
impracticable,  to  the  modern  oil  miller  or  refiner  in  this 
go-ahead  age,  and  scientific  progress  has  rendered  prac¬ 
ticable  the  production  of  an  oil  in  conformity  with  the 
needs  of  the  hour,  and  in  a  comparatively  limited  time. 
The  old  system  of  preparing  an  oil  for  the  varnish  kettle 
by  simply  submitting  a  well-settled  product  to  a  certain 
temperature,  about  200°  Fahrenheit,  for  several  hours. 


46 


THE  MANUFACTURE  OF  LINSEED  OIL. 


together  with  mechanical  agitation,  is  utterly  inadequate 
to  meet  modern  conditions.  The  risks  taken  by  old-time 
varnish  makers  of  an  oil  breaking  in  the  varnish  kettle, 
owing  to  atmospheric  or  other  conditions,  cannot  be 
tolerated  by  the  operator  of  to-day,  and  methods  are  now 
essential  for  the  production  of  a  refined  oil  undreamed 
of  in  former  times.  Not  infrequently  the  breaking  of  an 
oil  was  looked  upon  as  a  preliminary  stage  of  the  pro¬ 
cess  unavoidable  in  varnish  making. 

Before  concluding  this  treatise  on  the  treatment  of  lin¬ 
seed  oil  intended  for  use  in  varnish  making,  a  few 
observations  may  be  seasonably  introduced  with  regard 
to  sodium  chloride  (common  salt)  as  a  refining  factor. 


Salt  as  a  Refining  Agent  in  Linseed  Oil— Color  Drawback 
Which  Appears  in  an  Improperly  Treated  Oil. 


Several  years  ago  a  patent  was  secured  on  an  invention 
appertaining  to  linseed  oil  refining,  for  which  the  pat¬ 
entee  claimed  merits  of  a  very  superior  order  and  of  a 
nature  hitherto  unknown.  The  results  have  not  been  in 
accord  with  the  comprehensive  virtues  claimed  for  it, 
nevertheless  the  invention  is  not  without  profitable 
interest  to  the  progressive  refiner  and  varnish  maker.  In 
the  description  of  his  patent,  the  inventor  states  that  the 
objection  to  the  use  of  linseed  oil  in  varnish  making,  and 
in  the  formation  of  linoleums,  japans,  leather  treatment, 
&c.,  consists  in  its  tendency  to  separate — the  heavier 
from  the  lighter  parts  of  the  oil — when  submitted  to  a 
temperature  of  400°  or  500°  Fahrenheit.  This  separation, 
while  causing  a  serious  loss,  has  the  effect  of  producing 
a  varnish  nearly  black,  owing  to  the  action  of  the  accel¬ 
erated  temperature  on  the  heavier  or  gummy  substance. 
In  brief,  the  inventor  claimed  for  his  process  the  property 
of  firmly  uniting  the  heavier  and  the  lighter  parts  of 
the  oil,  so  that  heat  would  not  separate  them  when 
being  united  with  the  gums  to  form  varnishes.  By  mix¬ 
ing  the  oil  with  a  solution  of  common  salt  this  desirable 
consummation  was  said  to  be  accomplished.  Further¬ 
more,  the  removal  of  the  oleine  is  said  to  be  effected  in 
a  practical  manner  in  maintaining  the  oil  at  a  temperature 
of  110°  Fahrenheit  and  in  a  state  of  agitation  for  ten 
hours  in  each  of  from  nine  to  fourteen  days,  then  mixing 
while  hot  in  a  state  of  agitation  a  saline  solution,  and 
finally  drawing  off  the  saline  and  oleine  precipitate  and 
washing  the  oil  with  pure  water  until  a  further  precipitate 
is  obtained. 

One  of  the  peculiar  conditions  of  success  essential  in 

47 


48 


THE  MANUFACTURE  OF  LINSEED  OIL. 


the  prosecution  of  this  method,  according  to  the  patentee, 
consists  in  the  fact  that  while  old  and  therefore  well- 
settled  oil  requires  fourteen  days’  treatment,  the  new  oil 
requires  only  nine  days’  agitation. 

The  really  practical  part  of  the  invention  deserving  of 
the  attention  of  the  refiner  is  embodied  in  the  latter  part 
of  the  detailed  description.  Instead  of  using  mechanical 
agitation,  heat  can  be  advantageously  employed  for  ef¬ 
fecting  the  same  result,  in  which  case  the  saline  solution 
is  mixed  with  the  oil  at  the  outset,  and  the  mixture  is  sub¬ 
jected  to  a  heat  sufficient  to  boil  it.  This  heat  is  kept 
up  for  twenty-four  hours  and  the  precipitation  of  the 
oleine  will  take  place  on  cooling.  The  oleine  and  the 
saline  solution  are  then  run  off  together,  and  the  oil  is 
washed  with  pure  water  and  agitated  for  about  one  hour, 
when  a  second  deposit  is  obtained  and  removed  in  like 
manner. 

An  effective  saline  solution  can  be  prepared  by  dissolv¬ 
ing  ninety  pounds  of  salt  in  sixty  gallons  of  water  for 
each  ton  of  oil  to  be  treated.  To  brighten  the  oil  after 
being  washed  it  is  heated  to  about  200°  Fahrenheit.  This 
has  the  effect  of  driving  off  all  traces  of  moisture,  and 
leaves  the  oil  in  suitable  condition  for  the  final  process 
of  filtration. 

The  proximity  of  a  linseed  oil  refinery  to  salt  water 
may  be  used  to  excellent  advantage.  The  use  of  salt 
water  in  the  natural  condition,  in  conjunction  with  the 
sulphuric  acid  process  in  the  preparation  of  a  varnish 
oil  is  productive  of  more  satisfactory  results  than  can  be 
obtained  by  the  use  of  pure  water. 

As  a  refining  factor  it  is  therefore  apparent  that  salt 
suitably  introduced  in  the  oil  to  be  treated  plays  an  im¬ 
portant  part,  and  its  addition  to  the  refiner’s  store  for 
more  frequent  use  will  mark  a  decided  improvement  in 
the  general  treatment  of  linseed  oil.  It  is  incontrovertible 


THE  MANUFACTURE  OF  LINSEED  OIL. 


49 


that  this  question  has  not  received  the  consideration 
which  its  importance  deserves. 

At  times  the  refiner  will  turn  out  an  oil  with  a  greenish 
shade,  notwithstanding  the  application  of  treatment 
apparently  as  methodical  as  that  which  marks  his  reg¬ 
ular  work.  The  maker  of  fine  varnishes  objects  to  this 
peculiar  shade,  although  it  has  never  been  demonstrated 
that  an  oil  possessing  this  trait  proves  in  the  least  detri¬ 
mental  to  the  manufacture  of  a  superior  product.  Never¬ 
theless  its  presence  is  objectionable,  and  means  must  be 
discovered  to  eradicate  it.  This  will  probably  be  found  to 
be  a  somewhat  difficult  undertaking,  and  the  details  of  the 
various  operations  may  be  investigated  seriatim,  and  in 
the  most  painstaking  manner,  without  a  satisfactory  solu¬ 
tion  of  the  mystery.  Ultimately  the  source  of  the  dif¬ 
ficulty  may  be  traced  to  the  copper-lined  steaming  tanks, 
the  sides  of  which  may  be  coated  with  the  accumulated 
deposits  of  numerous  steamings  or  washings,  or  to  exces¬ 
sive  washings.  Copper  is  well  known  to  have  a  decided 
tendency  to  affect  oil  in  this  manner,  if  the  latter  is  too 
long  subjected  to  the  steaming  or  washing  process.  A 
gallon  of  linseed  oil  heated  in  a  small  copper  pot  up  to 
400°  Fahrenheit  will  present  on  cooling  a  much  darker 
shade  when  viewed  in  the  sample  phial  than  a  similar 
quantity  subjected  to  precisely  the  same  temperature, 
and  for  the  same  duration  of  time,  in  an  ordinary  iron 
pot.  Further  investigation  will  develop  the  fact  that 
prolonged  steaming  in  each  of  the  foregoing  small  lots 
will  reveal  a  strong  green  shade  in  the  oil  heated  in 
a  copper  receptacle. 

As  the  purpose  in  steaming  or  washing  the  refined  oil 
is  to  neutralize  the  traces  of  sulphuric  acid,  when  that 
refining  agent  is  used,  obviously  the  use  of  an  iron  pot 
becomes  impracticable  owing  to  the  corroding  action  of 
the  acid. 


50 


THE  MANUFACTURE  OF  LlNSEED  OIL. 


Prolonged  steaming  in  a  copper-lined  tank  has  a  ten¬ 
dency  to  fasten  the  color  in  the  oil.  On  the  other  hand, 
it  has  been  demonstrated  that  in  a  coniparatively  short 
period  of  steaming  a  greenish  shade  may  be  developed  in 
the  oil.  Subsequent  to  filtration  this  defect  is  apparent, 
but  careful  investigation  will  disclose  the  fact  that  ac¬ 
cumulated  coatings  in  steaming  tanks  are  present,  the 
removal  of  which  will  invariably  remedy  the  difficulty. 

Experience  is  the  true  guide  for  the  avoidance  of  the 
drawbacks  encountered  in  linseed  oil  refining. 

The  final  treatment  accorded  a  varnish  oil  consists  in 
its  filtration.  This  must  be  slowly  accomplished,  and, 
when  practicable,  by  gravity,  preferably  to  artificial  pres¬ 
sure.  The  oil  to  be  filtered  should  be  tanked  in  an 
elevated  position,  and  the  chamber  taps  of  the  filter  press 
set  so  that  a  series  of  minute  streams  will  pass  through 
the  filtering  medium  to  the  trough  beneath,  and  thence 
to  the  receiving  tanks. 

V^ery  much  greater  importance  is  attached  to  the  shade 
or  color  of  an  oil,  and  especially  its  bleached  aspect,  than 
the  ordinary  necessities  of  varnish  making  warrant. 

Just  why  a  demand  should  be  made  for  a  white  oil,  in 
the  majority  of  instances,  it  would  be  difficult  to  deter¬ 
mine.  For  the  superior  varieties  of  colorless  varnishes, 
however,  a  thoroughly  bleached  and  oxidized  oil  is  of 
peculiar  value.  But  it  is  incontrovertible  that  however 
light  colored  an  oil  may  be,  its  aspect  becomes  materially 
changed  when  the  chemical  and  resinous  ingredients 
are  added  to  the  heated  fluid  in  the  copper  or 
iron  treating  kettle.  The  term  “water-white”  may  be 
considered  as  simply  abstract  when  applied  to  prepared 
oil,  and  the  only  value  such  a  product  possesses,  other 
than  that  which  distinguishes  the  regular  variety,  con¬ 
sists  in  its  peculiar  aspect  being  a  positive  warrant  of 
having  been  thoroughly  refined. 


THE  MANUFACTURE  OF  LINSEED  OIL. 


51 


The  use  of  this  generally  expensive  oil  may  be  obviated 
by  purchasing  from  an  established  refiner,  or  when  the 
crude  oil  is  prepared  on  the  premises  of  the  varnish 
maker.  The  production  of  a  colorless  oil,  as  previously 
stated,  involves  considerable  expense,  and  unless  sus¬ 
tained  by  exceptionally  favorable  circumstances  will 
eventually  prove  unremunerative,  principally  owing  to 
the  fact  that  varnish  makers  being  assured  they  can 
obtain  an  oil,  perfect  in  all  respects,  although  not 
bleached  by  extreme  processes,  will  use  it  preferably  to 
a  product  which  costs  more,  and  which  has  no  better 
qualification  to  commend  it  other  than  being  lighter  in 
color. 

A  sample  of  prepared  oil  was  submitted  to  the  writer 
recently,  the  peculiar  features  of  which  deserve  con¬ 
sideration.  The  principle  involved  in  its  preparation 
consists  in  the  thickening  or  bodying  being  wholly  or 
in  part  governed  by  the  heat  application  and  general 
cooking  manipulation.  The  oil  in  question  appeared 
almost  colorless,  possessing  a  good  body,  and  absolutely 
free  from  flocculent  matter.  Briefly,  these  properties 
were  probably  produced  by  using  the  following  formula; 
By  subjecting  a  previously  prepared  oil  to  a  temperature 
of  600°  Fahrenheit  as  rapidly  as  possible,  at  which  point 
a  reversion  of  the  conditions  is  commenced,  which  con¬ 
sists  in  speedily  reducing  the  temperature  to  a  point 
below  100°  Fahrenheit,  or  to  the  normal  temperature — 
70°  Fahrenheit.  Upon  the  celerity  with  which  this 
change  is  brought  about  much  of  the  success  of  the 
process  depends.  A  covered  kettle  is  the  most  suitable 
receptacle  for  the  heating  process,  as  better  results  are 
obtainable  when  the  surface  of  the  oil  is  not  exposed  to 
the  air.  The  most  feasible  method  for  reducing  the 
temperature  is  by  passing  the  oil  through  a  water-tube 


52 


THE  MANUFACTURE  OF  LINSEED  OIL. 


cooler,  or  the  use  of  cooling  chambers  around  the  kettle 
will  effect  the  purpose  desired,  while  proving  an  excellent 
medium  for  regulating  the  temperature  during  the  cook¬ 
ing  process.  The  oil  is  then  allowed  to  settle  for  say  thirty 
hours  and  filtered,  at  which  point  a  deep  green  color 
will  pervade  it.  By  w’ashing  and  subsequent  settling, 
the  process  is  complete,  the  oil  being  now  almost  color¬ 
less,  possessing  a  good  body  and  without  perceptible 
odor.  About  5  per  cent  of  waste  may  be  counted  upon 
as  a  result  of  refining  by  this  method. 

In  the  manufacture  of  light  colored  varnishes  pos¬ 
sessing  great  body  consistency,  the  oil  must  be  rapidly 
heated  to  a  high  temperature  and  reduced  as  quickly  as 
possible  in  the  same  manner  as  that  described  in  the  fore¬ 
going  formula  when  practicable.  It  must  be  borne  in 
mind  that  the  superiority  of  the  finished  product  mater¬ 
ially  depends  upon  the  rapidity  with  which  the  increasing 
and  retrograding  temperatures  are  carried  out  respect¬ 
ively. 

The  removal  of  the  coagulable  substances  in  linseed  oil 
by  the  foregoing  processes,  precludes  the  possibility  of 
scum  accumulations  on  surface  of  the  oil  in  treating 
kettle — the  latter  being  a  reprehensible  feature  insep¬ 
arable  to  the  old  system.  The  fluid  is  now  in  suitable 
condition  for  the  prosecution  of  the  work  peculiar  to 
\arnish  making.  A  temperature  of  000°  Fahrenheit 
may  now  be  exerted  on  the  oil  without  deleterious  results, 
but  it  must  be  recognized  that  however  efficiently  the 
refining  process  may  have  been  carried  out,  if  the  sub¬ 
sequent  washings  have  not  adequately  removed  all  traces 
of  the  refining  agent — sulphuric  acid — the  unavoidable 
reaction  which  takes  place  in  the  treating  kettle  will 
have  the  effect  of  generating  gelatinous  matter,  or,  in 
other  words,  the  oil  will  break.  This  occurrence  is  an 


THE  MANUFACTURE  OF  LINSEED  OIL. 


53 


unmistakable  indication  that  defective  steaming  or  wash¬ 
ing  has  characterized  the  previous  treatment  of  an  oil, 
which  may  have  been  in  other  respects  properly  manipu¬ 
lated. 


Heating  Kettles— Uniform  Distribution  of  Temperature  in  an 
Oil  Under  Treatment  Essential  to  Success. 


The  complete  neutralization  of  all  acid  traces  becomes 
essential  in  the  production  of  superior  varnishes.  On 
occasions,  oil  has  been  known  to  separate,  or  break,  when 
undergoing  treatment,  although  the  principles  which 
governed  its  preliminary  preparation  may  have  been  un¬ 
exceptionable  from  any  standpoint.  Defective  cooking 
induced  by  improper  application  of  heat  is  responsible 
for  this  drawback.  The  necessity  of  procuring  a  tem¬ 
perature  throughout  the  oil  as  uniform  as  modern  appli¬ 
ances  will  permit,  becomes  otthe  greatest  moment.  An 
absolute  uniformity  of  temperature  throughout  the  oil 
in  the  ordinary  varnish  kettle  is  impossible  of  attain¬ 
ment,  and  the  varnish  maker,  however  experienced,  is 
incapable  of  turning  out  two  batches  exactly  alike  in 
color,  body,  drying  properties,  &c.,  although  made  from 
ingredients  similar  in  quality  and  quantity,  and  subjected 
to  the  same  manipulation. 

Owing  to  the  nature  of  the  prevailing  methods  and 
appliances,  an  insuperable  difficulty  presents  itself  in 
disseminating  a  uniform  temperature  throughout  the  oil 
under  treatment,  and  modern  science  has  failed  to  suc¬ 
cessfully  grapple  with  the  problem.  By  whatever  device 
employed,  having  for  its  object  the  uniform  distribution 
of  heat,  experience  has  demonstrated  the  impracticability 
of  procuring  a  temperature  alike  at  bottom,  sides  and 
surface  of  the  oil  in  the  kettle,  whether  of  the  movable  or 
stationary  variety.  That  portion  of  the  oil  resting  on 
bottom  of  the  kettle,  and  which  receives  in  full  force  the 
intensity  of  the  incandescent  heat  from  the  coke  fire  in 
a  direct  manner,  will  of  necessity  be  subjected  to  a  tem¬ 
perature  very  much  in  excess  of  that  which  the  ther- 

54 


THE  MANUFACTURE  OF  LINSEED  OIL. 


55 


mometer  reveals.  The  constantly  changing  position  of 
the  fluid  caused  by  the  stirring,  to  a  material  extent,  pre¬ 
vents  it  from  increasing  in  intensity  until  burning  sets 
in,  and  the  practical  operative  closely  observing  each 
recurring  phase  of  the  process,  and  guided  by  experience 
is  enabled  to  turn  out  with  a  reasonable  degree  of  cer¬ 
tainty  a  suitable  product,  the  ingredients  and  other  tech¬ 
nical  details  being  appropriate. 

Several  years  ago  a  form  of  kettle  was  introduced, 
which  had  its  origin  in  France,  by  means  of  which  sur¬ 
prising  results  were  said  to  have  been  acquired.  But  it 
must  be  said  that  experience  has  failed  to  confirm  the 
flattering  character  claimed  for  the  innovation.  On  the 
principle  of  the  water  bath  the  new  design  was  operated, 
and  its  construction  consisted  of  a  double  kettle,  with 
sufficient  space  between  to  permit  of  the  presence  of 
melted  lead,  tin  or  wax,  while  even  boiled  oil  was  sug¬ 
gested,  each  being  utilized  as  a  medium  for  transmitting 
heat  from  the  fire  to  the  treated  oil,  between  which 
elements  it  remained,  while  it  absorbed  and  imparted  the 
desired  temperature,  respectively. 

These  substances,  as  is  well  known,  melt  and  boil  at 
certain  specified  temperatures,  the  melting  and  boiling 
points  varying  materially  according  to  the  physical  com¬ 
position  of  each  product.  To  arrive  at  the  melting  or 
boiling  points,  respectively,  of  the  foregoing  ingredients 
a  certain  temperature  must  be  developed  at  top,  bottom 
and  sides  in  the  space  between  the  double  kettle  in  which 
the  fluid  is  placed,  and  maintained  in  that  condition.  It 
was  considered  that  absolute  uniformity  of  temperature 
could  be  procured  by  this  means,  with  comparative  facil¬ 
ity,  and  transmitted  in  precisely  the  same  condition  to 
the  oil  in  the  inner  kettle.  Laboratory  experiments  gave 
indications  of  the  practicability  of  this  desirable  action, 
but  while  satisfactory  on  a  small  scale,  its  applicability 


56 


THE  MANUFACTURE  OF  LINSEED  OIL. 


in  practical  form  on  a  manufacturing  basis,  proved  ut¬ 
terly  inadequate. 

No  definite  set  of  rules  may  be  established  for  the  pro¬ 
secution  of  the  work  peculiar  to  varnish  making,  but 
each  operative  must  be  guided  by  his  knowledge  of  the 
action  of  the  various  ingredients  in  the  several  stages 
of  the  process  in  the  production  of  the  particular  quality 
of  varnish  he  has  in  view.  It  is  of  the  greatest  moment 
that  the  fire  should  be  in  that  condition  which  best 
promotes  a  strong  heat  radiation,  so  that  the  latter  may 
impinge  on  the  lower  part  of  the  kettle  uninterruptedly. 
Flames  and  smoke — the  results  of  combustion  in  its 
incipient  stages — should  be  exhausted  prior  to  the  intro¬ 
duction  of  the  oil  into  the  kettle  for  treatment.  The  fire 
should  be  of  an  incandescent  character  and  well  devel¬ 
oped.  Coke  is  recognized  as  being  the  best  fuel  material 
for  suitably  advancing  perfect  combustion  and  maintain-  • 
ing  same  in  a  uniform  manner,  the  development  of  flame  • 
and  smoke  being  comparatively  limited.  Every  varnish  j 
maker  recognizes  the  fact  that  with  the  advantages  i 
derived  from  the  use  of  the  most  superior  ingredients  in  j 
the  manufacture  of  fat  varnishes — oils,  gums,  chemicals  i 
and  thinners — the  prospect  of  turning  out  a  faultless  " 
product  may  be  irrecoverably  spoiled  by  neglect  of  these 
precautionary  measures. 

The  prolongation  of  excessive  temperature,  without 
previous  treatment  of  a  special  nature,  will  result  in  . 
giving  color  to  the  oil,  and  should  not  be  maintained 
more  than  one  hour,  the  maximum  point  being  about  ; 
G00°  Fahrenheit,  while  570°  Fahrenheit  marks  the  limit  ' 
with  many  operatives.  '  J 

It  is  well-known  that  oxidation  is  developed  with  1 
greater  effect  when  the  oil  is  rapidly  heated.  j 

Reference  has  been  made  to  the  fact  that  by  rapidly  J 
heating  the  oil  to  the  desired  temperature,  and  vice  versa,  « 


THE  MANUFACTURE  OF  LINSEED  OIL. 


a  heavy  body  will  be  imparted  to  the  fluid.  This  prop¬ 
erty  may  be  increased  by  repeating  the  process,  but  it 
is  essential  to  commence  the  second  heating  under  pre¬ 
cisely  the  same  conditions  as  those  which  governed  the 
first;  that  is,  a  fresh  fire  must  be  prepared  for  the  final 
heating.  For  special  purposes,  where  the  use  of  an 
intensely  oxidized  oil  is  called  into  requisition,  the  fore¬ 
going  heating  and  cooling  processes  may  be  repeated 
a  number  of  times  until  the  desired  consistency  is 
attained.  In  the  practice  of  this  oxidizing  and  bodying 
principle,  it  was  discovered  that  the  cooling  of  the  oil 
very  frequently  delayed  the  progress  of  the  work  to  a  very 
considerable 'extent,  and  to  expedite  matters,  an  excellent 
device,  designated  a  heat  exhauster,  was  introduced.  The 
mechanically  cooling  process  simply  consists  of  forcing  a 
current  of  cold  air  through  a  pipe,  the  end  of  which  rests 
on  the  bottom  of  the  varnish  kettle,  and  removing  the 
same  when  it  arrives  at  the  surface  of  the  oil  by  a  suction 
or  exhausting  contrivance.  This  is  effected  by  connect¬ 
ing  the  pipe  from  the  hood  which  is  suspended  imme¬ 
diately  over  the  kettle,  to  a  rapidly  revolving  fan  wheel, 
which  is  conveniently  situated  adjoining  the  chimney, 
to  facilitate  the  force  and  volume  of  the  air  draught. 

The  fan  or  exhausting  wheel  may  be  operated  from  the 
most  convenient  counter-shaft.  The  rapidity  with  which 
it  sweeps  the  ascending  air  from  the  surface  of  the  oil 
renders  it  a  valuable  factor  in  the  preparation  of  this 
quality  of  oil,  and  its  use  becomes  indispensable  when 
the  product  is  treated  in  the  stationary  kettle.  In  the 
preparation  of  oil  for  lithographic  ink  and  other  special 
purposes  where  good  flowing  properties  are  essential,  the 
use  of  the  heat  exhauster  is  of  the  greatest  moment. 


Oxidizing  Agents  of  Linseed  Oil  and  Their  Correct  Use— Oxon- 

ized  Air. 


To  still  further  oxidize  an  oil,  borate  of  manganese  is 
brought  into  requisition,  without  detriment  to  the  color. 
1.  here  are  a  number  of  ingredients  which  effect  the  same 
object  in  a  satisfactory  manner,  such  as  oxide  of  man¬ 
ganese,  sugar  of  lead,  sulphate  of  zinc,  or  the  lead  oxides, 
litharge  and  red  lead.  These  chemicals,  without  excep¬ 
tion,  impart  a  deep,  dark  color  to  the  oil,  and  more  espe¬ 
cially  the  two  latter.  In  the  production  of  boiled  oils 
for  general  painting  purposes,  the  metallic  oxides  re¬ 
ferred  to  stand  in  good  favor. 

d'o  impart  intense  oxidizing  properties  to  a  prepared  oil 
without  darkening  it,  becomes  an  important  matter  in  the 
manufacture  of  superior  varnishes.  The  oxidation  of  oil 
by  atmospheric  influences  alone  is  inadequate,  and  the 
aid  of  oxidizing  compounds  to  increase  its  drying  prop¬ 
erties  becomes  indispensable. 

Laboratory  experiments  have  demonstrated  that  hot 
air  produces  a  very  superior  drying  oil,  and  has  the 
effect  of  rapidly  thickening  the  fluid  when  uniformly 
disseminated  throughout  the  oil,  resembling  somewhat 
blown  rape-seed.  But  on  a  large  scale  the  results  of 
this  oxidizing  process  may  prove  disappointing.  To 
produce  an  oil  having  the  desired  body  consistency,  the 
operation  must  be  maintained  continuously  to  an  extent 
— with  regard  to  time — at  variance  with  all  factory  ideas, 
ftom  thirty  to  forty  hours,  leaving  out  of  the  question 
the  expense  involved.  About  five  years  ago  a  varnish 
firm  constructed  an  apparatus  having  for  its  object  the 
heating  of  air  to  be  used  for  the  oxidation  of  varnish 
oil,  and  costing  in  the  neighborhood  of  £10,000.  After 
five  or  six  attempts  had  been  made  to  produce  the  hoped- 
for  results,  the  operation  of  the  apparatus  was  found  im¬ 
practicable,  and  in  consequence  was  abandoned. 

58 


THE  MANUFACTURE  OF  LINSEED  OIL. 


59 


Oxonized  air  has  been  shown  to  impart  very  superior 
properties  to  linseed  oil — with  regard  to  thickening  and 
drying — but  as  in  the  foregoing  instance,  the  impracti¬ 
cability  of  producing  the  invisible  fluid  in  its  pure  state, 
and  in  sufficient  rpiantities,  remains  an  insuperable  bar¬ 
rier  to  progress  in  that  direction.  A  method  of  giving 
body  to  the  prepared  varnish  oil,  and  in  general  use  in 
large  refineries,  consists  of  blowing  air  through  a  mass 
of  oil,  the  latter  being  at  a  temperature  of  200°  Fahr. 
This  also  has  the  effect  of  drawing  off  latent  moisture  that 
may  be  present  subsequent  to  the  washing  process,  and 
is  continuously  maintained  for  about  four  hours,  the  ap¬ 
paratus  consisting  of  a  steam- jacketed  kettle. 

By  submitting  refined  linseed  oil  to  further  treatment, 
which  consists  of  forcing  oxygen  gas  through  the  mass, 
a  very  superior  drying  oil  is  obtained  without  changing 
the  original  color.  But  in  tliis  instance  the  metallic 
oxide  used  in  the  preparation  of  the  oxygen — peroxide 
of  manganese — is  treated  separately  in  a  retort,  and  at  a 
high  temperature  the  fluid  is  conveyed  to  the  “bottom  of 
the  treating-kettle,  passing  through  the  oil  to  the  sur¬ 
face  as  soon  as  it  is  produced.  The  oil  should  be  pre¬ 
viously  heated  to  a  temperature  of  about  300°  Fahren¬ 
heit. 

Metallic  oxides,  such  as  litharge  or  red  lead,  very 
materially  increase  the  absorbing  properties  of  linseed 
oil  for  oxygen,  which  when  applied  to  the  surface  dries 
hard  and  firm.  But  a  dark  color  is  unavoidably  imparted 
to  the  oil  thus  treated,  and  while  rendering  it  of  great 
value  as  a  boiled  oil  intended  for  painting  purposes,  it 
proves  detrimental  in  the  manufacture  of  the  higher 
grades  of  varnish. 

Of  all  oxidizing  metallic  substances,  probably  borate  of 
manganese  takes  the  lead  as  being  the  most  powerful. 

The  rule  which  is  generally  adhered  to,  in  the  ma- 


60 


THE  MANUFACTURE  OF  LINSEED  OIL. 


jority  of  instances,  with  regard  to  the  oxidation  of  oil, 
consists  in  combining  lead  and  manganese  driers.  The 
quantity  and  nature  of  the  driers  incorporated  with  oil, 
the  mode  of  application  and  extent  of  temperature,  ma¬ 
terially  govern  the  quality  of  the  finished  product. 

Umber,  in  the  preparation  of  boiled  oils,  finds  con¬ 
siderable  favor,  and  is  valuable  according  to  the  propor¬ 
tion  of  manganese  it  contains.  Its  propensity  to  darken 
the  oil  limits  its  use  in  the  preparation  of  varnish  oil. 

By  conducting  the  boiling  operation  in  a  closed  vessel, 
having  first  withdrawn  the  air,  thereby  removing  the 
atmospheric  influence,  an  oil  may  be  boiled  without  the 
usual  discoloration  which  a  boiling  in  the  open  kettle 
presents.  In  order  to  thicken  the  oil,  if  necessary,  air 
could  be  blown  in  subsequent  to  the  incorporation  and 
blending  of  the  drying  ingredients  with  the  oil.  A  safety 
valve  will  permit  the  escape  of  the  accumulated  vapors 
and  gases  when  the  pressure  has  reached  the  releasing 
point. 

According  to  Van  Wagner,  borate  of  manganese  be¬ 
comes  an  excellent  siccative  when  added  to  raw  linseed 
oil,  one  part  to  a  1,000  of  oil.  In  the  preparation  of  a 
superior  drying  oil,  the  combination  of  lead  and  man¬ 
ganese  oxides  is  desirable.  It  readily  unites  with  the  oil 
and  renders  very  excellent  drying  properties  in  the  fin¬ 
ished  product. 

In  the  preparation  of  driers  various  bodies,  which 
comprise  salts  of  iron,  lead,  manganese  and  zinc,  are 
called  into  requisition,  and  Prof.  Hurst’s  comprehensive 
list,  which  includes  the  compounds  most  used  in  oils, 
paints  and  varnishes,  may  be  here  cited:  red  lead,  lith¬ 
arge,  lead  acetate,  lead  borate,  manganese  oxide,  man¬ 
ganese  sulphate,  manganese  borate,  manganese  oxalate, 
zinc  oxide,  zinc  sulphate  and  ferrous  sulphate.  There  are 
other  substances,  however,  such  as  borax  and  salam- 


THE  MANUFACTURE  OF  LINSEED  OIL. 


61 


nioniac,  which  possess  the  properties  of  promoting  a  per¬ 
fect  assimilation  of  the  oxides  and  oil,  and  lessening  the 
fluidity  of  the  latter,  respectively,  which  are  utilized  on 
special  occasions. 

The  combination  which  uniformly  gives  the  most  satis¬ 
factory  results  in  the  preparation  of  driers  and  japans 
consists  in  the  use  of  black  oxides  of  manganese,  of 
which  there  are  two  varieties.  It  is  conceded  by  compe¬ 
tent  authorities  that  the  black  manganese  contains  a 
larger  proportion  of  oxygen  than  other  varieties  of 
that  oxide,  and  is,  therefore,  a  powerful  drying  factor 
in  the  composition  of  boiled  oils,  paints  and  certain 
classes  of  varnish.  Unfortunately,  its  proclivity  to 
darken  the  oil  precludes  its  use  in  the  preparation  of 
light-colored  varnishes. 

FILTERING  MEDIUMS - MODE  OF  RENOVATING,  ETC. 

The  combination  of  cloth  and  paper  will  prove  very 
effective  in  the  production  of  a  perfectly  clarified  linseed 
oil,  and  may  be  strongly  recommended  in  the  case  of 
prepared  oils  and  as  well  for  varnishes.  To  produce 
an  absolutely  clarified  oil  by  means  of  a  filter  press,  with, 
say,  fifty  plates,  thirty-two  "inches  square,  400  gallons 
per  day  should  be  the  maximum  output;  while  if  the  cir¬ 
cumstances  permit,  from  250  to  200  gallons  would  be 
preferable.  When  practicable,  the  pressure  should  be  by 
gravity,  otherwise  the  feed  pump  should  be  operated  with 
the  slowest  movement  possible,  which  will  be  found  ade¬ 
quate  to  keep  up  supply. 

Laboratory  experiments  by  the  writer  have  also  con¬ 
clusively  established  the  impracticability  of  utilizing 
paper  as  a  filtering  medium  when  the  oleaginous  fluid 
contains  moisture.  Several  small  sheets  of  filter  paper 
were  placed  in  a  large  glass  funnel,  and  in  the  cavity  thus 
formed,  one  quart  of  oil,  to  which  a  fractional  percentage 
of  water  had  been  previously  added,  was  poured.  The 


62 


THE  MANUFACTURE  OF  LINSEED  OIL. 


first  rim  of  oil  was  perfectly  bright,  thus  demonstrating 
that,  to  a  certain  point,  the  paper  retained  the  moisture, 
but  subsequently  the  fluid  became  cloudy,  exhibiting 
no  further  improvement  until  the  operation  was  termi¬ 
nated.  A  close  investigation  revealed  the  fact  that  after 
the  first  run  of  oil  had  passed  through  the  paper  in  a 
clarified  and  transparent  condition,  the  latter  became 
charged  with  moisture  retained  from  the  same,  while  the 
succeeding  flow  of  oil  from  the  filter  press  contained  the 
original  and  full  proportion  of  moisture,  the  filtering 
medium  being  disqualified  for  further  use  as  a  clarify¬ 
ing  agent. 

In  the  case  of  crude  or  prepared  oil  filtration,  the  pro¬ 
cess  may  be  maintained  uninterruptedly  for  weeks,  con¬ 
ditional  upon  the  fluid  being  free  from  moisture,  and 
until  the  increased  pressure  shown  on  the  press  gauge 
indicates  the  necessity  of  removing  the  accumulations 
in  the  chambers,  and  washing  the  filtering  material, 
when  textile  fabric  is  used  if  necessary.  In  the  case  of 
varnish  filtration,  also,  when  the  operation  is  regularly 
maintained  during  the  day,  the  filtering  material,  if 
paper,  can  be  used  similarly,  but  in  the  event  of  the 
press  standing  inactive  for  twenty-four  hours,  it  will  be 
necessary  to  change  the  paper  for  the  succeeding  opera¬ 
tion,  by  reason  of  the  varnish  having  dried  and  closed 
the  pores  of  the  paper,  rendering  it  unfit  for  further  use. 
To  avoid  this  drawback  it  is  necessary  to  keep  the  filter¬ 
ing  medium  saturated  with  oil,  which  may  be  effected  by 
passing  a  continuous  stream  through. 

In  the  filtration  of  superior  oil,  intended  for  special 
purposes,  fine  filter  cloths  are  sometimes  used,  the  pro¬ 
cess  being  slow,  but  results  are  invariably  of  a  satisfac¬ 
tory  nature. 

In  the  ordinary  work  of  crude  oil  filtration,  when 
cloths  have  been  scraped  several  times,  it  will  be  dis- 


THE  MANUFACTURE  OF  LINSEED  OIL. 


63 


covered  that  the  intervals  in  which  good  work  may  be 
effected  will  become  gradually  diminished  until  removal 
and  washing  become  necessary.  Not  the  least  important 
function  devolving  on  those  whose  duty  it  is  to  keep  the 
filter  press  or  presses  in  thorough  working  order  con¬ 
sists  in  their  possessing  a  correct  knowledge  of  how  to 
prolong  the  duration  of  service  of  the  filtering  fabric  to 
the  possible  limit.  On  more  than  one  occasion  the 
writer  has  seen  an  excellent  set  of  lamb’s  wool  filter 
cloths  utterly  ruined  by  mismanagement. 

The  same  objection  which  is  made  to  permitting  the 
filtering  material,  when  paper,  to  become  dried  up, 
causing  the  pores  to  become  clogged,  is  applicable  with 
greater  force  when  the  medium  is  cloth.  The  latter  should 
not  be  allowed  to  remain  in  the  press  longer  than  ten 
or  twelve  hours  without  being  moistened  with  oil ;  other¬ 
wise,  where  a  perfect  system  of  washing  is  not  thor¬ 
oughly  understood,  the  cloths  are  rendered  unfit  for  fur¬ 
ther  use.  Washing  by  means  of  the  most  approved  sys¬ 
tem  will  not  fully  restore  cloths  which  have  been 
neglected  and  allowed  to  gum  up;  hence,  the  necessity 
of  judicious  treatment  in  the  care  of  same. 

In  several  of  the  forms  of  varnish  filter  press  pre¬ 
viously  described,  after  removal  of  the  filtering  medium 
the  interior  is  thoroughly  cleansed  by  continuously  pass¬ 
ing  through  benzene  or  turpentine  for  a  fixed  brief 
period,  but  experience  has  demonstrated  that  this  is  an 
expensive,  as  well  as  an  ineffective,  method.  An  alkaline 
solution  composed  of  caustic  soda  and  hot  water  will  be 
found  more  economical  and  serviceable.  The  solution, 
caused  to  pass  through  the  machine  in  the  foregoing 
manner,  will  remove  the  adhering  matter  by  saponifica¬ 
tion,  after  which  a  strong  stream  of  water  forced  through 
the  pump  and  filter  press  will  effectually  remove  all  loose 
particles  of  gumming  matter  and  other  impurities.  Care 


64 


THE  MANUFACTURE  OF  LINSEED  OIL. 


must  be  exercised  in  allowing  ample  time  for  the  ma¬ 
chine  to  dry  before  being  again  put  in  operation. 

Cloths  which  need  restoring  should  be  washed  singly 
in  benzene  to  effect  a  thorough  cleansing.  This  is  ef¬ 
fected,  where  no  better  appliances  are  available,  by  tak¬ 
ing  each  cloth  singly  and,  after  submersion  in  benzene, 
subjecting  them  to  a  thorough  scrubbing  by  means  of  an 
ordinary  scrub-brush  on  any  conveniently-arranged  plat¬ 
form.  The  adhering  wax-like  substance,  which  clogs 
the  texture,  may  by  this  means  be  thoroughly  removed, 
the  cloths,  after  sufficient  time  has  elapsed  for  the  com¬ 
plete  evaporation  of  the  volatile  fluid,  being  in  good  or¬ 
der  again  for  the  execution  of  satisfactory  work.  This 
cleansing  process  is  arduous  and  tedious,  as  well  as  be¬ 
ing  expensive — objections,  however,  which  may  be  ob¬ 
viated  by  the  use  of  an  excellently-constructed  hand¬ 
washing  machine,  especially  designed  to  meet  the  re¬ 
quirements  of  the  case. 

The  machine  referred  to  will  cleanse  one  heavy  or  two 
light  filter  cloths  in  a  rapid  and  effective  manner.  The 
rapid  movement  of  a  lever  subjects  the  fabric  to  a  thor¬ 
ough  churning  or  agitation  in  benzene.  This  is  pro¬ 
duced  by  wooden  projections  on  the  under  surface  of  a 
movable  cover,  the  latter  being  actuated  by  the  lever 
referred  to.  By  the  aid  of  this  machine  two  men  can  re¬ 
move  a  set  of  thirty-six  heavy  and  light  filter  cloths, 
thoroughly  wash  and  replace  them  in  the  press  ready  for 
use,  in  from  ten  to  twelve  hours.  In  the  event  of  steam 
heat  being  used  to  hasten  the  evaporation  of  the  ben¬ 
zene  which  the  washing-machine  wringer  has  left  in  the 
cloths,  this  period  may  be  considerably  abridged.  The 
location  selected  for  drying  the  cloths  should  be  one  in 
which  air  freely  circulates.  The  escaping  vapors  must 
be  unconfined;  otherwise  disastrous  results  may  ensue. 
Probably  the  best  method  of  heating  the  cloths  after 


THE  MANUFACTURE  OF  LINSEED  OIL. 


65 


washing  for  the  purpose  of  drying  consists  in  the  use  of 
a  specially-constructed  heater,  composed  of  two  oblong 
sheets  of  boiler  iron,  connected  at  ends  and  sides,  form¬ 
ing  a  two  or  three-inch  chamber  between.  Steam  is 
permitted  to  enter  at  one  end  and  exhaust  at  the  other, 
the  heat  radiating  therefrom  rapidly  drying  the  cloths, 
which  latter  are  placed  on  the  heater.  Care  must  be  ex¬ 
ercised  in  changing  the  cloths  at  the  proper  time  to 
avoid  over-heating.  In  the  event  of  time  not  being  a 
consideration  in  the  prosecution  of  this  work,  the  cloths 
will  dry  very  thoroughly  if  exposed  to  the  sun  or  left 
over  during  the  night  in  a  suspended  position. 

Another  excellent  device  in  the  form  of  a  filter-cloth 
washing  machine  consists  of  an  apparatus  which  auto¬ 
matically  raises  the  rubbing  surface  free  from  the  cloths 
and  benzene  at  the  end  of  each  revolution,  returning, 
pounds  and  turns  them,  taking  a  new  hold  each  time 
and  rubbing  in  a  new  place.  This  combination,  or  triple 
action,  resembles  the  process  of  hand-rubbing,  with  a 
reduced  percentage  of  wear  and  tear,  and  requires  but 
little  physical  effort  to  actuate  it. 

Before  proceeding  further  on  the  subject  concerning 
the  filter  press,  a  few  more  hints  of  a  practical  nature 
concerning  filtration  will  be  in  order.  To  procure  best 
results  varnish  or  linseed  oil  should  be  filtered  when  cold. 
This  applies  with  equal  force  in  the  case  of  prepared  oil, 
and  for  the  reason  that  in  these  products  fatty  sub¬ 
stances  are  present,  soluble  at  a  temperature  above  140° 
Fahrenheit,  which,  when  filtered  at  the  normal  tempera¬ 
ture,  are  retained  by  the  filtering  medium;  but  when 
filtered  at  an  accelerated  temperature,  equivalent  to,  or 
in  excess  of,  the  foregoing  limit,  will  pass  in  solution 
with  the  oil  through  the  closest  medium — paper,  cloth 
or  felt — to  subsequently  reappear  in  the  oil  after  a  brief 
period  of  repose.  In  the  treatment  of  superior  oils  and 


66 


THE  MANUFACTURE  OF  LINSEED  OIL. 


varnishes  best  results  are  attainable  by  securing  the  use 
of  fine  filtering  material — whether  lambskin,  felt,  or 
paper — the  inferior  filtering  mediums  being  more  ap¬ 
propriate,  if  used  at  all,  in  the  filtration  of  new  oil,  as 
previously  referred  to. 

The  oil  or  varnish  manufacturer,  or  those  identified 
with  oils  in  a  practical  way,  without  the  use  of  the  filter 
press,  is  behind  the  times,  and  neglectful  of  his 
best  interests.  Here  are  a  few  of  the  advantages  gained 
by  the  filter  press  over  the  old-time  methods  of  separat¬ 
ing  impurities  from  oleaginous  fluids: 

1.  Economy  of  space.  The  method  adopted  of  dis¬ 
tributing  the  filtering  surface  in  the  filter  press  secures  an 
enormous  filtering  area  within  a  comparatively  small 
space. 

2.  Saving  of  time.  What  formerly  took  months  to  ac¬ 
complish  by  subsidence  in  the  settling  tank  can  now  be 
done  in  a  very  brief  period  by  the  filter  press. 

3.  Under  suitable  treatment,  a  complete  separation  of 
the  impurities  from  the  oil  or  varnish. 

In  the  case  of  cottonseed  oil  refining,  as  well  as  in 
lards  and  greases,  fuller’s  earth  is  used  as  a  refining 
agent.  The  latter  during  filtration  is  collected  in  the 
form  of  compact  cakes,  containing  a  certain  proportion 
of  the  oil  or  grease,  which  latter  can  be  thoroughly  re¬ 
moved  and  secured  by  steaming  the  cake  before  taking 
it  from  the  press,  no  subsequent  handling  being  neces¬ 
sary. 

The  filtering  area  of  round  metal  plate  press,  18  inches 
in  diameter  and  containing  20  chambers,  is  43  square 
feet,  the  thickness  of  cake  permissible  by  width  of  cham¬ 
bers  being  1  inch,  while  with  plates  and  extension  rings 
the  thickness  of  cake  can  be  more  than  quadrupled 
-A.  36-inch  plate  press  of  40  chambers  contains 
534  square  feet,  the  size  of  the  cake  being  in 


THE  MANUFACTURE  OF  LINSEED  OIL. 


67 


the  ratio  of  increase,  with  or  without  extension 
rings.  In  the  square-plate  press  the  increased 
area  over  the  circular,  almost  within  the  same 
compass,  is  deserving  of  consideration.  The  IS-inch 
plate  press,  square,  contains  80  square  feet  of  filtering 
area,  as  compared  with  43  square  feet  of  the  circular 
variety,  each  having  20  chambers. 

THE  SETTLING  TANK  OR  CLARIFIER. 

As  an  auxiliary  to  the  filter  press,  and  a  valuable  ac¬ 
quisition  to  modern  oil  milling,  the  use  of  a  small  settling 
tank,  or  clarifier,  immediately  beneath  each  set  of 
presses,  may  be  strongly  recommended.  By  its  aid  the 
necessity  of  frequent  cleaning  of  receiving  tanks  is  en¬ 
tirely  removed,  the  foots  being  secured  in  concentrated 
form  and  in  a  most  convenient  manner. 

Recently  the  writer  designed  and  set  up  six  of  these 
excellent  clarifying  tanks,  and  it  is  a  safe  assumption 
that  no  linseed  or  cottonseed  crusher,  knowing  their 
value,  would  be  without  them  longer  than  the  necessary 
time  to  construct  and  put  them  in  operation.  Its  utility 
is  practically  unknown,  and  it  is  a  matter  for  surprise  that 
such  a  valuable  and  economical  factor  should  have  so 
long  remained  dormant. 

The  first  form  of  clarifier  was  introduced  in  a  Chicago 
mill,  and  is  circular  and  conical.  It  is  estimated  that  by 
means  of  this  clarifier  about  nine  pounds  of  thick,  mealy 
matter  may  be  obtained  from  500  gallons  of  oil.  How¬ 
ever,  the  quantity  of  foots  obtained  depends  considerably 
on  the  form  of  the  hydraulic  press  plate?  and  the  general 
cooking  system  of  the  crushed  seed  which  obtains.  This 
proportion  may  be  exceeded  in  certain  cases,  and  vice 
versa.  It  is  evident  that  if,  by  any  means,  the  heavy  sedi¬ 
ment  or  foots  is  separated  from  the  oil  immediately  after 
it  falls  from  the  presses  and  prior  to  filtration,  the  latter 


68 


THE  MANUFACTURE  OF  LINSEED  OIL. 


process  will  be  very  materially  facilitated,  while  protect-  . 
ing  and  lengthening  the  duration  of  service  of  the  filter¬ 
ing  material  correspondingly. 

The  tank  is  simply  a  huge  funnel-shaped  vessel. 
The  capacity  is  140  gallons,  and  the  dimensions 
are  7  feet  long  and  feet  wide  at  top, 

and  9  feet  deep  over  all,  the  material  be¬ 
ing  ^-inch  steel,  and  may  be  readily  constructed  in  any 
boiler-making  establishment.  A  3-inch  plug  cock  must 
be  adjusted  at  the  bottom,  and  not  a  valve,  the  steep 
pitch  of  the  apparatus  carrying  the  mealy  matter  direct 
from  the  top  to  the  point  of  discharge.  By  means  of  in¬ 
terior  top  flanges  the  tank  may  be  suspended  from  the 
ceiling  immediately  beneath  the  presses,  and  one  of  the 
foregoing  dimensions  will  suffice  for  a  set  of  five  or  six 
presses.  In  the  centre,  also  suspended,  but  in  a  slightly  , 
more  elevated  position  than  the  settling  tank,  a  capacious 
funnel  of  tin  or  galvanized  iron  receives  the  several 
streams  of  oil  as  they  flow  from  the  respective  presses. 
Of  necessity,  the  fluid  and  mealy  matter  are  carried 
down,  the  clear  oil  rising  from  beneath  and  encircling 
the  exterior  of  the  funnel,  until  the  Overflow  is  reached 
at  the  point  indicated.  Nothing  but  comparatively  clear 
oil  thus  escapes  to  the  filter-press  tank,  while  at  stated  in¬ 
tervals — say  twice  each  week — the  attendant  will  re¬ 
move  the  mealy  matter  in  a  pail  by  opening  the  cock 
partially,  shutting  it  off  sharply  the  instant  the  liquid  ap¬ 
pears.  The  operation  may  now  be  maintained  in¬ 
definitely,  the  cost  of  construction  being  the  first  and 
only  expense  involved  by  the  introduction  of  the  system. 

The  overflow  pipe  must  lie  four  or  five  inches  below 
the  top  of  the  tank.  The  first,  or  circular,  form  of  clari¬ 
fying  tank  was  operated  with  a  coil  of  one-inch  steam 
pipe  running  around  the  interior,  but  for  the  reasons 
previously  considered — that  an  accelerated  temperature 


THE  MANUFACTURE  OF  LINSEED  OIL. 


69 


has  the  effect  of  assimilating  the  mucilaginous  or 
gummy  matters  with  the  oil  during  the  period  said  tem¬ 
perature  is  maintained.  A  series  of  these  clarifiers  could 
be  constructed  for  a  large  mill,  or  a  single  one,  with  cor¬ 
respondingly  increased  capacity,  would  produce  similar 
results,  if  the  character  of  the  surroundings  necessitated 
the  measure;  the  former  should  have  the  preference, 
however,  when  practicable.  In  the  event  of  the  circular 
cone-shaped  tank  being  selected,  care  must  be  exercised 
in  giving  sufficient  pitch  to  the  cone;  otherwise  the 
foots  will  lodge  on  the  sloping  sides  instead  of  working 
to  the  bottom  as  desired.  With  suitable  pitch,  as  de¬ 
scribed,  no  apprehension  need  be  entertained  of  the  pos¬ 
sibility  of  the  foots  failing  to  pass  out  upon  the  partial 
opening  of  the  three-inch  cock.  To  lessen  or  increase 
the  size  of  the  latter  will  be  harmful.  The  triangular¬ 
shaped  tank  has  many  advantages  over  the  circular  one. 
not  the  least  being  the  fact  that  the  greater  part  of  the 
apparatus — the  bulky  and  unwieldy  portion — presents 
no  obstacle  to  the  regular  mill  operations  by  being  in  an 
elevated  position,  the  lower  part,  tapering  to  a  point, 
giving  ample  clearance. 

STORAGE  TANKS — LATEST  METHODS  OF  STORAGE. 

In  addition  to  the  appliances  heretofore  described  con¬ 
cerning  the  equipment  of  a  boiling  and  refining  plant,  it 
will  be  necessary  to  refer,  for  a  brief  period,  to  the  de¬ 
sign  of  the  various  makes  of  storage  tanks,  together 
with  the  material  of  which  they  are  composed — attach¬ 
ments,  etc. 

Covered  tanks,  made  of  bright  tinned  iron,  hooped 
when  of  large  capacity,  and  furnished  with  screw  bung, 
together  with  gauge-glass,  similar  to  the  regular  furnace- 
boiler  water  gauge-glass,  with  index,  will  be  found 
economical,  as  well  as  convenient,  in  the  storage  of  vola¬ 
tile  fluids.  Similarly  constructed  tanks,  complete  with 


70 


THE  MANUFACTURE  OF  LINSEED  OIL. 


dipper,  fitted  with  lock  or  other  taps — in  both  varieties — 
together  with  wooden  under-supports  to  carry  the  weight 
of  oil  or  varnish,  in  addition  to  the  usual  metallic  bottom, 
are  very  desirable  acquisitions.  The  lids  are,  in  some  in¬ 
stances,  made  half  open  or  fitted  with  screw  bung. 

For  raising  the  temperature  of  water,  for  oil  refining 
(especially  in  the  preparation  of  varnish  oils),  and  for 
other  purposes  where  a  steam  pressure  not  exceeding  ten 
or  twelve  pounds  per  square  inch  is  needed,  the  double¬ 
case  heating  tank  fills  a  long-felt  want.  The  heating 
tanks  referred  to  are  made  on  an  improved  principle, 
being  especially  adapted  for  heating  and  mixing  pur¬ 
poses.  The  inner  and  outer  shells  are  riveted  and  hooped 
at  the  top,  and  at  the  bottom  are  two  inches  apart.  The 
bottom  of  the  inner  shell  is  concave,  and  the  outer  casing 
convex,  and,  meeting  in  the  centre  of  the  bottom,  form  a 
cavity  for  the  steam,  while  being  peculiarly  well  adapted 
to  resist  pressure  of  the  latter.  At  the  point  where  the 
two  bottoms  meet  in  the  centre  they  are  securely  riveted. 
They  are  strongly  hooped  and  provided  with  flanges  for 
steam  inlet  and  outlet,  draw-off  cock  for  condensed 
water,  and  flange  for  main  draw  off  tap  or  tube.'  They 
are  made  in  various  sizes,  the  capacity  ranging  from  50 
to  200  gallons. 

The  double-cased  or  steam-jacketed  high-pressure 
kettle  is  deserving  of  special  mention.  P'or  rosin  melt¬ 
ing,  or  mixing  of  various  substances  where  a  compara¬ 
tively  high  temperature  is  imperative,  it  is  peculiarly  well 
adapted.  The  tank  or  kettle  is  made  from  the  best 
selected  mild  steel  plates,  and  is  constructed  to  stand  a 
steam  pressure  of  60  pounds  per  square  inch.  Standing 
on  three  or  four  strong  angle-iron  feet,  riveted  on,  the  in¬ 
side  casing  is  all  solid  welded,  and  free  from  the  objec¬ 
tionable  rivet  heads.  There  are  also  two -solid  wrought- 
iron  blocks  securely  riveted  to  the  pan,  one  for  outlet  of 


THE  MANUFACTURE  OF  LINSEED  OIL. 


71 


condensed  steam,  and  the  other  for  inlet,  while  the  cas¬ 
ings  are  stayed  from  inner  to  outer  shells,  both  on  the 
sides  and  bottom.  The  capacity,  in  gallons,  of  the  various 
sizes  ranges  from  35  to  150  gallons. 

The  Anderson  improved  jacket  kettle  of  Cleveland, 
Ohio,  possesses  advantages  of  a  very  superior  charac¬ 
ter.  The  kettle  is  fitted  with  a  special  steam  trap,  which 
removes  steam  condensation  as  soon  as  formed,  prevent¬ 
ing  loss  of  steam.  The  kettle  is  guaranteed  not  to  leak 
or  get  out  of  order,  requiring  but  little  attention,  for  the 
reason  that,  as  soon  as  steam  is  turned  on  the  jacket,  the 
trap  will  regulate  the  blow-off.  For  this  reason  it  has 
gained  very  considerable  popularity,  while  the  economy 
established  by  its  use  is  directly  traceable  to  the  fact  that 
the  very  best  possible  results  are  obtained  by  means  of 
the  least  possible  supply  of  steam. 

A  comparatively  recent  innovation  in  the  method  of 
storing  varnish,  at  once  simple  and  possessing  decided 
advantages  over  the  older  system,  is  deserving  of  the  con¬ 
sideration  of  those  unfamiliar  therewith.  As  the  latter 
has  been  introduced  by  a  very  limited  number  of  manu¬ 
facturers,  and  is,  therefore,  not  generally  understood,  not¬ 
withstanding  its  simplicity,  detailed  particulars  at  this 
time  will  be  in  order.  As  a  means -of  rapidly  developing 
the  desirable  properties  of  a  fat  varnish,  prepared  oil, 
and  drier  of  all  varieties,  the  new  system  is  without  a  com¬ 
peer,  and  no  varnish  plant  may  be  considered  completely 
equipped  lacking  this  invaluable  adjunct.  A  double- 
bottomed,  steam-heating  tank  is  all  that  is  necessary  to 
accomplish  the  results  referred  to.  By  increasing  the 
temperature  of  the  stored  fluid,  whether  oil  or  varnish, 
in  a  comparatively  short  period  a  clarified  product  will 
be  obtained,  the  subsidence  of  the  impurities,  or  inert 
materials,  with  which  the  product  may  have  been  pre¬ 
viously  treated  being  very  materially  expedited  by 


72 


THE  MANUFACTURE  OF  LINSEED  OIL. 


rendering  the  contents  of  the  tank  increased  in  fluidity, 
due  to  the  accelerated  temperature.  As  a  preliminary 
step  to  the  filtration  of  raw  oil,  of  whatever  variety,  by 
thus  effecting  a  thorough  subsidence  of  the  mucilagin¬ 
ous  and  other  impure  substances,  a  brilliant  oil  is  pro¬ 
duced,  while  the  duration  of  service  of  the  filtering 
medium,  whether  paper,  felt  or  cloth,  is  correspondingly 
prolonged.  The  elimination  of  the  objectionable  matter 
prior  to  filtration  obviously  protects  the  filtering  medium, 
and,  as  previously  stated,  the  oil  should  be  allowed  suffi¬ 
cient  time  to  cool  before  being  filtered,  if  best  results  are 
to  be  obtained.  In  the  storage,  therefore,  of  all  varieties 
of  treated  oils  results  are  obtained  in  two  or  three  weeks 
by  means  of  the  double-bottomed,  steam-heated  tanks, 
which  require  five  or  six  months  when  stored  in  the 
ordinary  settling-tank.  In  the  latter  variety  of  storage 
tank,  it  will  be  readily  understood  that  when  a  treated 
oil,  after  it  has  been  allowed  the  necessary  time  to  cool 
in  the  cooking  kettle,  has  been  run  into  said  tank,  the 
chemical  ingredients  which  were  used  as  oxidizing 
agents,  and  which  render  the  product  turbid,  precipitate 
slowly,  thus  indefinitely  prolonging  the  clarification  pro¬ 
cess.  On  the  other  hand,  by  prolonging  an  increased 
temperature  the  oil  is  thinned,  thus  facilitating  the  sub¬ 
sidence  of  the  impurities,  otherwise  held  in  suspension 
when  the  oil  is  cold  and,  therefore,  of  increased  viscosity. 
It  is  well  known  that  treated  oils,  after  having  been  placed 
for  cold  storage  in  the  old  tanking  system,  thicken  in 
twenty-four  hours,  thus  proving  a  barrier  to  rapid  and 
effective  subsidence — a  drawback  which  is  obviated  by 
the  system  described. 

The  advantages  obtained  by  the  use  of  storage  tanks 
constructed  of  material  such  as  previously  referred  to  over 
those  in  ordinary  use,  such  as  large  ones  constructed  of 
boiler-plate,  are  manifold.  The  two  most  important  are 


THE  MANUFACTURE  OF  LINSEED  OIL. 


73 


low  prime  cost,  as  compared  with  other  systems,  and  ex¬ 
cellent  facilities  for  re-arrangement.  A  series  of  tanks  of 
500  gallons  each — ten  in  number,  holding  in  all  5,000 
gallons — complete  with  index,  cover,  taps,  and  pipe  con¬ 
nection,  may  be  constructed  at  a  comparatively  small 
cost.  The  system  permits  of  almost  endless  varieties  of 
arrangement — a  matter  of  great  consideration  and  utility 
in  the  varying  requirements  and  changes  in  trade.  An 
individual  tank  can  be  instantaneously  cut  out  of  circuit 
for  repairs.  They  can  be  arranged  in  places  of  irregular 
form  that  longer  and  square  tanks  would  not  fit  into, 
and  by  means  of  the  index  the  quantity  of  liquid  con¬ 
tained  therein  may  be  ascertained  at  a  glance.  For  oil, 
petroleum,  spirits,  and  other  fluids,  the  use  of  this  form  of 
tank  may  be  strongly  commended. 

FILTER  PUMPS. 

With  regard  to  the  design  of  pump  best  adapted  to  the 
requirements  of  thorough  oil  or  varnish  filtration,  the 
duplex  variety  will  be  found  very  superior  to  the  single 
pump.  In  fine  filter-press  work,  the  fluid  must  be  uni¬ 
formly  pushed,  not  punched,  in  the  press — an  occurrence 
which  is  unavoidable  in  the  use  of  the  single  pump. 
Messrs.  Stilwell-Bierce  &  Smith-Vaile  Company,  of 
Dayton,  Ohio,  have  designed  an  excellent  pump  of  the 
duplex  variety  for  filter-press  work.  The  pump  is  made 
of  all  iron,  brass,  or  bronze  on  liquid  ends,  according  to 
the  views  of  the  manufacturer.  The  plunger  is  packed  on 
the  outside,  and  is,  therefore,  easily  accessible,  while  re¬ 
movable  cylinders,  brass  or  copper  lined,  are  also  special 
features  of  this  form  of  pump.  There  are  several  other 
makes  of  filter-press  pump,  each  of  which  possesses  pecu¬ 
liar  and  advantageous  features,  well  suited  to  the  re¬ 
quirements  of  the  case. 


74 


THE  MANUFACTURE  OF  LINSEED  OIL. 


AIR  PUMPS. 

Improved  blowing  or  air  engines  are  now  largely  used 
for  agitating  oils,  acids,  and  chemical  preparations,  as 
well  as  for  ventilating  purposes.  They  are  usually  con¬ 
structed  on  the  direct-acting  system,  compact  and  simple. 
The  machine  is  now  ranked  among  the  indispensable 
requirements  of  a  well-equipped  plant.  In  the  admixture 
of  the  sulphuric  acid  with  the  oil  in  the  refining  process, 
no  system  known  can  compare  with  the  thorough  agita¬ 
tion  and  commingling  of  the  fluids  as  obtained  by  the  use 
of  a  reliable  air  pump.  No  costly  foundations  are  neces¬ 
sary  when  setting,  while  the  expense  for  attendance  and 
maintenance  is  but  a  fractional  item.  The  Henry  R. 
Worthington  Pump  Works  have  a  very  excellent  form  of 
air  pump  on  the  market.  A  feature  of  the  pump  deserv-- 
ing  of  special  mention  consists  in  the  compensating  valve 
motion,  enabling  the  length  of  stroke  to  be  readily  and 
finely  adjusted,  so  that  the  pistons  can  be  made  to  travel 
close  up  to  the  heads  of  the  air  cylinders,  thus  combining 
greatest  economy  in  use  of  steam,  together  with  efficient 
work.  The  air  valves  are  not  liable  to  derangement,  and 
are  of  very  durable  form.  The  air  pistons  are  made 
light  and  strong,  and  are  furnished  with  adjustable  pack¬ 
ing  of  improved  design.  The  pump  is  made  in  various 
sizes  and  capacities,  the  steam  and  air  cylinders  ranging 
in  diameter  from  4  and  4^  inches  to  24  and  48  inches,  re¬ 
spectively.  An  air  pump  liable  to  become  deranged  at 
the  critical  period  when  the  acid  is  introduced  to  the  oil, 
or  at  any  period  during  the  agitating  or  mixing  process, 
is  a  very  dangerous  appurtenance  to  a  varnish  plant. 
Its  use  is  most  reprehensible,  and  is  equivalent  to  a  di¬ 
rect  invitation  to  disaster.  On  several  occasions  the 
writer  has  seen  batches  of  oil  charred  and  utterly  spoiled 
for  the  intended  purpose,  owing  to  this  cause.  Having 


THE  MANUFACTURE  OF  LINSEED  OIL. 


75 


these  circumstances  in  view,  the  value  of  a  reliable  ma¬ 
chine  will  be  more  fully  appreciated. 

FILTER  PRESSES. 

Since  the  use  of  the  filter  press  is  finding  its  way  into 
almost  every  branch  of  industry,  a  short  account  of  the 
machines  manufactured  by  the  original  maker  may  be  in¬ 
teresting.  The  present  style  of  filter  presses  was  intro¬ 
duced  into  this  country  in  1860  by  Mr.  A.  L.  G.  Dehne. 
Since  that  time  he  has  made  constant  improvements  in 
them,  and  has  so  perfected  them  that  they  now  enjoy  a 
wide  reputation  for  high  efficiency  and  irreproachable 
workmanship. 

The  principal  advantages  of  the  filter  press  are: 

1st.  The  largest  possible  filtering  surface  in  the  small¬ 
est  possible  space. 

2d.  The  facility  for  forcing  the  material  through  the 
filtering  medium  (cloth)  by  the  most  suitable  pressure. 
This  varies  from  a  slight  hydrostatic  pressure  to  140  tbs, 
per  square  inch. 

3d.  The  ease  with  which  the  filter  press  may  be 
handled. 

THE  FILTER  PRESS — CORRECT  MODE  OF  OPERATION,  ETC. 

The  introduction  of  the  filter  press  in  oil  milling  and 
varnish  manufacture  filled  a  long-felt  want  by  removing 
many  of  the  inconveniences  coincident  thereto,  while  be¬ 
ing  an  economical  factor  of  material  import.  A  patent 
was  first  obtained  by  the  Messrs.  Johnson,  of  London,  on 
the  filter  press,  about  fifteen  years  ago,  since  which  time 
its  use  has  become  widespread  in  lines  where  its  introduc¬ 
tion  became  practicable  throughout  the  manufac¬ 
turing  world.  IN'Iessrs.  John  Johnson  &  Co.,  of 
59  Franklin  street.  New  York,  was  formerly  a 
branch  of  the  London  house,  but  the  business 


76 


THE  MANUFACTURE  OF  LINSEED  OIL. 


of  filter  press  making,  in  all  its  forms,  is  car¬ 
ried  on  by  the  New  York  house  as  a  distinct  and 
separate  firm.  The  house  has  a  national  reputation,  and 
the  business,  as  conducted  to-day,  is  in  a  most  flourishing 
condition.  The  form  of  press  originally  introduced  con¬ 
sists  of  eighteen  chambers,  each  of  eighteen  inches  diam¬ 
eter,  but  subsequently  larger  ones  were  constructed,  and 
are  now  in  general  use  in  the  leading  oil  mills.  In  var¬ 
nish  manufactories,  however,  a  press  is  used  having  simi¬ 
lar  measurements  to  the  former,  but  with  increased  num¬ 
ber  of  chambers.  The  original  form  has  been  altered  to 
suit  special  recjuirements,  and  many  varieties  and  makes 
of  filter  press  are  now  on  the  market,  differing  in  design, 
though  identical  in  principle,  each  presenting  advantages 
peculiar  to  themselves.  There  are  a  large  number  of  filter 
press  manufacturers  in  England  and  the  United  States, 
to  the  best  makes  of  which,  coming  within  the  scope  of 
this  treatise,  we  purpose  extending  consideration.  It 
must  be  conceded  that  the  makers  of  the  filter  press  in 
the  United  States  have  made  very  considerable  progress 
with  regard  to  efficiency,  durability,  and  simplicity  of 
construction.  In  the  various  industrial  arts  in  which  fil¬ 
tration,  or  percolation,  advances  manufacturing  interests, 
the  modern  filter  press  must  be  accorded  the  highest  posi¬ 
tion.  This  applies  with  peculiar  emphasis  to  oil  milling 
and  varnish  making.  For  the  removal  or  separation  of 
solids  held  suspended  in  liquids,  such  as  mucilaginous 
and  other  objectionable  impurities  in  crude  linseed  oil, 
the  adaptability  of  the  filter  press  is  peculiarly  advan¬ 
tageous.  In  the  clarification-  of  oils  and  varnishes,  the  fil¬ 
ter  press  has  a  wide  application,  while  being  rapidly  ex¬ 
tended,  mechanical  filtration  having  very  largely  super¬ 
seded  the  old  system  of  subsidence  effected  by  protracted 
settling,  the  only  method  heretofore  available  for  the 
separation  of  objectionable  matter  present  in  oleaginous 


I 


THE  MANUFACTURE  OF  LINSEED  OIL. 


77 


THE  JOHNSON  filter  PRESS. 

or  Other  fluids.  The  loss  of  time  necessary  to  procure 
the  desired  results,  together  with  the  concurrent  expense 
attached  thereto  being  considered,  the  merits  of  the  filter 
press  as  an  economic  factor  in  the  production  of  a  per¬ 
fectly  clarified  product  in  a  comparatively  brief  period, 
will  be  more  fully  appreciated.  The  use  of  the  filter  press 
removes  probably  the  most  objectionable  feature  in  oil¬ 
milling,  heretofore  unavoidable.  The  retention  of 
the  “foots,”  or  mealy  matter,  in  the  filter  cham¬ 
bers,  precludes  the  necessity  of  frequent  storage- 
tank  cleaning,  while  the  practicability  of  their  be¬ 
ing  reworked  in  the  kettle  in  an  expeditious  and 
effective  manner  is  very  materially  improved, 
owing  to  their  being  in  concentrated  form.  The 
waste  involved  in  the  practice  of  the  old  system,  whether 


78 


THE  MANUFACTURE  OF  LINSEED  OIL. 


in  the  protracted  period  essential  for  the  removal  of  the 
foots  from  the  storage  tanks — a  circumstance  of  frequent 
occurrence — the  inconvenience  experienced  by  loss  of  the 
storage  room  occupied  by  the  casks  and  barrels  of  foots 
awaiting  their  final  disposition,  together  with  the  cost  of 
preparing  same  in  the  form  of  a  suitable  admixture 
with  the  regular  material  from  the  rolls,  or  ground  cake, 
for  the  purpose  of  being  suitably  reworked  in  the  kettle, 
taken  collectively,  amount  to  a  very  large  item  of  ex¬ 
pense  annually  in  an  average-sized  oil  mill.  It  is 
palpable,  therefore,  that  an  oil  mill  of  whatever  capacity, 
and  however  well  equipped  in  other  respects,  cannot  be 
considered  to  be  complete,  with  regard  to  suitable  ap¬ 
pliances  for  the  prosecution  of  economical  work,  lacking 
this  most  useful  adjunct. 

Until  within  the  last  few  years  the  form  of  filter  press 
designed  for  oil  milling  consisted  of  a  thirty-six-inch  fil¬ 
ter  with  thirty-six  chambers,  which  is  in  operation  to-day 
in  many  manufactories;  but  in  the  event  of  additions  be¬ 
ing  needed  to  the  filtering  capacity,  or  the  installation 
of  new  plants,  later  and  improved  presses  are  selected 
preferably.  In  the  old  form  of  filter  press  the  plates  are 
covered  with  suitable  filtering  cloths,  which  consist  of 
two  sets  of  fabrics  held  in  position  by  three  adjustable 
fastenings  on  the  centre  and  sides  of  the  upper  edge  of 
the  plates.  The  equipment,  with  regard  to  the  filtering 
medium,  is  comprised  in  one  set  of  heavy  texture,  being 
next  to  the  plate,  and  an  outer  set  of  lighter  material. 
Not  the  least  important  condition  in  the  attainment  of 
satisfactory  results  consists  in  the  filtering  material  being 
of  the  correct  grade  and  texture.  The  fabric  must  be 
strong,  yet  woven  closely,  so  that  while  producing  a  clear 
fluid,  it  must  be  sufficiently  tenacious  to  successfully 
withstand  the  extra  pressure  always  exerted  where  the 
joints  are  formed.  In  the  filtration  of  raw  linseed  oil,  the 


THE  MANUFACTURE  OF  LINSEED  OIL. 


79 


writer  has  used  for  years  a  fabric  specially  prepared,  and 
by  means  of  which  impurities  are  removed  from  the  oil 
in  a  most  perfect  manner,  and  which,  with  judicious  treat¬ 
ment,  may  be  kept  in  practical  operation  for  at  least  a 
year,  the  Johnson  filter  press  having  been  used. 
Further  along  in  this  treatise  instructions  will  be  given 
concerning  the  treatment  which  should  be  accorded  the 
filter  cloths,  whether  in  or  out  of  use,  the  best  mode  of 
cleansing  and  removing  the  gummy  accumulations  which 
clog  the  fabric,  together  with  other  important  details  con¬ 
nected  therewith. 

With  the  cloths  suitably  adjusted,  the  plates  are  forced 
together  by  the  follower,  which  is  actuated  by  a  screw 
operated  by  the  lever-wheel.  The  plates  are  recessed,  so 
that  a  chamber  is  formed  between  each  two  plates,  the 
rim  or  outer  edge  of  the  latter  being  finished  to  a  uniform 
thickness,  while  being  of  sufficient  width  to  form  tight 
joints  and  prevent  tearing  or  rending  of  the  cloths.  The 
concave  surfaces  of  the  plates  have  vertical  grooves,  in 
which  the  liquid  may  pass  off,  the  drainage  being  in¬ 
creased  by  several  short,  straight  grooves,  running 
laterally  across  the  first  ones,  at  stated  distances  apart, 
toward  the  plate  bottom,  in  which  is  located  the  outlet. 
The  plates  being  forced  together  the  press  is  now  ready 
for  work.  The  oil  is  pumped  into  the  press  and,  passing 
through  the  cloths,  courses  down  the  grooves  referred 
to,  and  through  the  outlet  into  the  receptacle  beneath,  a 
perfectly  clarified  product,  the  residue  or  mealy  matter 
being  retained  in  the  chambers  by  the  filtering  medium. 
The  capacity  of  this  press  is  about  20  tons  of  oil  daily,  al¬ 
though  this  quantity  may  be  exceeded  under  certain 
conditions.  Presses  without  accompanying  engine,  and 
pump  fitted  and  geared  thereto,  are  preferable,  the  direct 
steam-acting  pump  usually  producing  best  results,  with 
regard  to  being  less  prone  to  get  out  of  order. 


Practical  Points  Concerning  the  Filter  Press,  Whether  for  Oil 
or  Varnish  Filtration,  and  Where  the  Best  Form  of 
Filtering  IMedium  May  Be  Obtained. 


In  the  event  of  the  press  being  required  to  remain  idle 
for  a  few  days,  a  simple  but  effective  method  of  keeping 
the  cloths  moistened,  and  thereby  preserved,  without  the 
necessity  of  removing  them  from  the  plates  for  submer¬ 
sion,  consists  in  charging  the  press  with  oil,  the  outlets 
being  shut.  This  is  impracticable,  however,  where  shut¬ 
off  taps  are  not  fitted  to  the  plates;  but  the  liquid  may  be 
slowly  pumped  through,  the  oil  continuously  coursing 
from  suction  tank  to  press,  and  return.  By  repeating  this 
operation  at  frequent  intervals,  the  material  is  preserved. 

When  through  omission,  or  from  any  other  cause,  fil¬ 
ter  cloths  used  in  the  clarification  of  linseed  oil  are  per¬ 
mitted  to  dry  up  during  a  temporary  cessation  of  the  fil¬ 
tering  operation,  the  damaging  effect  on  the  material  is 
more  serious  than  in  the  case  of  cottonseed  oil  filtration. 
The  drying  properties  of  linseed  oil  act  very  deleteriously 
on  the  surface  of  the  cloths  by  gumming  them,  thus 
blocking  the  minute  openings  between  the  woven 
threads,  rendering  them  impervious  to  the  oil,  and  con¬ 
sequently  valueless  as  a  filtering  medium. 

Cottonseed  oil,  which  possesses  drying  properties  to  a 
comparatively  trifling  extent,  is  not  so  injurious  to  the 
cloths  when  permitted  to  remain  thereon;  nevertheless, 
complete  submersion  guarantees  preservation  of  the  fab¬ 
ric  when  out  of  use  for  any  extended  period. 

The  cloth  used  in  the  filtration  of  lard  oil,  being  of  the 
same  texture,  requires  similar  attention  under  like  cir¬ 
cumstances.  The  coagulation  of  the  albuminous  de¬ 
posits  characteristic  of  animal  oils  displays  a  tendency  to 
clog  the  filtering  material  when  not  submerged  in  the 

80 


THE  MANUFACTURE  OF  LINSEED  OIL. 


81 


liquid.  This  has  the  effect  of  damaging  them  equally 
with  that  of  the  gumming  tendency  of  linseed  oil  under 
similar  conditions. 

Impressed  with  the  fallacious  supposition  that  a  saving 
is  effected  in  cost  of  filtering  material,  some  of  the 
cottonseed  crushers  and  refiners  have  substituted  several 
plies  of  cotton-duck  cloth  on  each  plate  of  the  filter  press 
for  the  closely-woven  and  substantial  fabric  especially 
manufactured  for  that  purpose.  The  use  of  such  material 
is  most  reprehensible;  and  viewed  from  a  practical  and 
economical  standpoint,  should  not  be  maintained  under 
any  condition  whatsoever.  To  obtain  an  oil  from  which 
the  ordinary  proportion  of  vegetable  matter  has  been 
eliminated,  as  is  the  case  where  a  suitable  filtering  me¬ 
dium  is  utilized,  by  means  of  such  flimsy  material  as  the 
common  fabric  referred  to,  becomes  a  practical  impossi¬ 
bility.  The  tendency  of  the  duck  cloth  to  rend  at  the 
joints  augments  the  difficulty  by  permitting  the  oil  to 
pass  out  unfiltered,  thus  materially  contributing  to  the 
defective  principle  involved;  that  is,  the  attainment  of 
perfect  filtration  by  inadequate  means. 

Not  infrequently  leaks  occur  by  reason  of  the  im¬ 
practicability  of  forming  permanently  tight  joints,  the 
cheap  material  separating  under  the  pressure  essential  to 
form  a  perfect  joint.  At  this  juncture  the  screw  is  set 
up,  thus  bringing  the  plates  closer,  the  object  being  to 
stop  the  leak  or  leaks;  but  while  this  expedient  may  for 
the  moment  prove  effective,  aided  probably  by  the  dis¬ 
lodged  foots  in  the  filter  chambers  forced  to  the  leaky 
point  by  the  escaping  fluid,  and  blocking  the  aperture  or 
apertures  temporarily,  the  extra  pressure  exerted  at  the 
joints,  as  a  result  of  the  latest  movement  of  the  screw, 
will  eventually  manifest  itself  by  still  further  increasing 
the  undesirable  oil  exit,  until  perforce  the  operation  is 
brought  to  a  standstill.  The  press  is  then  permitted  to 


82 


THE  MANUFACTURE  OF  LINSEED  OIL. 


drain  off  its  fluid  contents,  the  fragmentary  cloth  or 
cloths  are  removed,  to  be  substituted  by  whole  material, 
which,  in  turn,  is  destined  to  be  similarly  cast  aside,  prob¬ 
ably  before  the  expiration  of  forty-eight  hours. 

The  use  of  filter  cloths  of  suitable  texture  is  much 
more  economical,  actually  costing  less  in  the  end,  with¬ 
out  reference  to  the  very  superior  product  obtained  by  its 
use  as  compared  with  that  of  the  frailer  material.  Under 
skillful  treatment,  a  set  of  soiled  and  clogged  filter  cloths 
can  be  restored  to  their  original  usefulness,  or  so  closely 
approaching  it,  that  the  difference  is  not  perceptible; 
and  this  may  be  successively  repeated  as  occasion  re¬ 
quires,  until  they  are  worn  out  by  prolonged  usage.  Lack 
of  adequate  knowledge  to  effect  a  thorough  cleansing 
of  the  soiled  cloths,  in  nine  cases  out  of  ten  is  the  prim¬ 
ary  cause  of  their  being  irrecoverably  spoiled,  thus  pre¬ 
cipitating  their  premature  abandonment.  It  is  oppor¬ 
tune  to  observe  at  this  point  that  the  house  of  J.  H. 
Lane  &  Co.,  110  Worth  street.  New  York,  handles  a 
line  of  filter  cloths  which  are  of  a  very  excellent  charac¬ 
ter.  The  writer  has  used  their  cloths  for  many  years 
with  uniform  satisfaction,  and  takes  pleasure  in  recom¬ 
mending  them. 

OIL-BOILING  AND  VARNLSH  THERMOMETERS. 

A  perfect  thermometer  may  be  rendered  absolutely  un¬ 
reliable  by  injudicious  treatment  during  a  single  opera¬ 
tion.  Among  the  primary  causes  which  induce  defects 
in  a  varnish  thermometer  may  be  mentioned  the  repre¬ 
hensible  system  of  permitting  the  instrument  to  rest  on 
the  kettle  bottom  during  the  whole,  or  part,  of  the  period 
essential  in  the  preparation  or  treatment  of  an  oil  or  var¬ 
nish.  In  the  position  referred  to,  the  instrument  is 
brought  into  close  proximity  with  the  fierce  heat,  always 
most  intense  in  that  particular  location,  especially  when 
the  material  requires  heating  quickly  to  a  high  tempera- 


83 


THE  MANUFACTURE  OF  LINSEED  OIL. 

I  

ture.  A  temperature  of  600°  Fahrenheit,  registered  at  a 
point  near  the  surface  of  a  body  of  oil  or  varnish,  in  the 
treating-kettle,  indicates  a  very  much  increased  tempera¬ 
ture  at  the  bottom,  where  the  intense  and  unobstructed 
heat  of  an  incandescent  fire  impinges  most  forcibly.  With 
certain  makes  of  thermometers,  the  sudden  transition 
from  the  normal  temperature  to  this  highly  intensified 
heat  has  the  immediate  effect  of  agitating  the  measur¬ 
ing  liquid  in  the  tube,  and,  in  its  rapid  and  spasmodic  as¬ 
cent,  causing  separation.  On  the  other  hand,  by  deposit¬ 
ing  the  thermometer  in  an  atmosphere  of  low  tempera¬ 
ture,  or  on  the  surface  of  a  cold  or  damp  floor,  immedi¬ 
ately  subsequent  to  the  completion  of  a  batch  of  oil  or 
varnish,  the  results,  with  regard  to  their  bearing  on  the 
instrument,  are  equally  pernicious.  The  thermometer  or 
thermometers  should  be  carefully  introduced  into  the 
heated  liquid,  or,  better  still,  the  instruments  should  be 
suspended  in  the  oil  before  the  application  of  heat,  the 
mercury  gradually  ascending  in  the  tube,  together  with 
the  rising  temperature.  The  effect  of  a  high  temperature 
on  the  thermometer  is  not  injurious  by  impairing  its  ac¬ 
curacy  when  handled  in  this  manner. 

An  excellent  form  of  thermometer  now  in  use  in  many 
American  varnish  manufactories,  and  of  comparatively 
recent  construction,  may  be  subjected  to  the  sudden 
change  from  low  to  high  temperature  without  apparent 
deleterious  results,  but  the  foregoing  method  is,  never¬ 
theless,  to  be  commended  in  all  instances. 

A  distinct  clearance  of  six  inches  should  obtain  be¬ 
tween  the  lower  point  of  the  instrument  and  the  kettle 
bottom.  The  exact  temperature  necessary  to  procure  a 
certain  oil  or  varnish  being  absolutely  arbitrary,  it  fol¬ 
lows  that  an  accurately  defined  scale  of  readings,  which 
is  engraved  on  the  tube  or  facing  of  the  instrument,  when 
undergoing  the  process  of  calibration,  becomes  an  in- 


84 


THE  MANUFACTURE  OF  LINSEED  OIL. 


dispensable  condition  in  modern  varnish  making.  The 
most  perfect  type  of  thermometer  will,  however,  exhibit 
inaccuracies  if  used  regularly  for  a  year,  even  under 
favorable  conditions,  thus  demonstrating  the  necessity 
of  regular  tests.  The  most  serviceable  type  of  varnish 
thermometer  consists  in  the  lower  part  of  the  column 
or  bulb,  which  contains  the  mercury,  and  which  is,  in 
turn,  enclosed  in  a  metallic  shell,  being  protected  by  a 
small  frame  composed  of  six  arms  extending  downwards, 
and  uniting  at  a  central  point  beneath,  the  frame  being 
about  4^  inches  in  length.  This  affords  effective  protec¬ 
tion  to  the  most  vulnerable  part  of  the  instrument,  and 
being  simply  screwed  to  the  bottom,  may  readily  be  re¬ 
moved  for  cleaning  or  other  purposes.  In  other  designs, 
a  perforated  metallic  guard  is  attached  to  the  bottom,  re¬ 
movable  in  a  similar  manner. 

Complaints  from  varnish  makers  are  of  frequent  oc¬ 
currence  with  regard  to  the  unreliable  character  of  their 
thermometers  and  frequent  proclivity  to  get  out  of  or¬ 
der,  the  fault  in  the  majority  of  instances  resting  with 
themselves.  On  the  completion  of  a  batch  of  oil  or  var¬ 
nish  instead  of  handling  with  the  greatest  care,  the  heed¬ 
less  operative  will  seize  the  instrument  and  throw  it  into 
an  obscure  place  as  a  valueless  object,  repeated  treatments 
of  this  character  not  only  causing  twists  and  bends  in  the 
frame,  but  also  displacing  from  its  central  position  the 
metallic  shell  which  immediately  protects  the  bulb.  Fur¬ 
thermore,  neglect  of  a  thorough  renovation  or  cleaning 
after  each  operation  will,  like  the  foregoing  censurable 
methods,  undoubtedly  impair  the  sensitiveness  of  the  in¬ 
strument,  however  perfectly  constructed.  Recently  the 
writer  examined  a  thermometer  which  the  oil  boiler  com¬ 
plained  of  as  being  misleading,  and  found  that  the  in¬ 
terior  of  the  perforated  guard  was  entirely  filled  with 
burnt  resinous  and  other  substances,  the  accumulation 


THE  MANUFACTURE  OF  LINSEED  OIL. 


85 


of  numerous  operations.  The  radiating  rays  of  heat,  in 
this  instance,  were  obstructed  by  the  accumulations  re¬ 
ferred  to,  and,  failing  to  act  upon  the  mercury  in  the  bulb 
in  a  direct  manner,  the  scale  readings  were  necessarily  in¬ 
accurate.  A  thorough  cleansing  should  succeed  each 
operation,  and  this  is  most  expeditiously  and  satisfac¬ 
torily  prosecuted  by  the  aid  of  benzine.  Partially  cal¬ 
cined  gum  or  resinous  accumulations  are  by  this  means 
removed  with  facility,  thus  maintaining  the  sensitive¬ 
ness  of  the  instrument  unimpaired  for  the  succeeding 
operation. 

In  the  preparation  of  oils  and  varnishes,  it  is,  there¬ 
fore,  imperative  that  an  accurate  instrument  be  used,  the 
best  interests  of  the  manufacturer  being  subserved  by  a 
recognition  of  the  fact. 

The  writer  has  used  for  a  number  of  years,  with  entire 
satisfaction,  a  design  of  thermometer  peculiarly  adapted 
for  the  needs  of  oil  boiling  and  varnish  making.  The 
design  referred  to  has  been  invented  by  the  Hohmann 
&  Maurer  Manufacturing  Company,  with  offices 
at  123  Liberty  street.  New  York,  and  works  at 

Rochester,  N.  Y.  This  well-known  house  has 
experimented  for  eighteen  years  with  thermometers  for 
use  in  oil  boiling  and  varnish  making,  Vv^ith  the  result 
that  it  is  beyond  question,  the  most  reliable  and  practi¬ 
cal  thermometer  on  the  market  to-day  for  its  various 
uses.  The  construction  of  the  design  of  thermometer 
referred  to  is  essentially  substantial,  thus  lessening  the 
chances  of  breakage.  The  scale  case,  which  is 

graduated  from  212°  to  700°  Fahrenheit,  is  made 
of  pure  aluminum  casting,  and  in  triangular  form, 
thus  imparting  strength  and  facility  for  hand¬ 
ling.  The  scales  or  dials  are  hermetically  sealed 
by  a  removable  glass  joint,  secured  by  screws 
to  the  body  of  the  frame,  the  joint  being  grooved 


86 


THE  MANUFACTURE  OF  LINSEED  OIL. 


and  packed.  The  figures  and  graduations  are  a  dead 
white  against  a  jet  black  background,  which  greatly 
facilitates  reading,  the  dimensions  of  the  scale  case  be¬ 
ing  14  by  2f  inches,  the  entire  length  being  under  40 
inches.  The  thermometer  tube,  with  the  long  cylindrical 
mercury  bulb,  is  encased  in  a  metallic  shell,  and  held  in 
position  by  means  of  a  suitable  packing  screw  and  stuff¬ 
ing  box,  the  packing  material  being  asbestos.  For  pre¬ 
parations  which  do  not  require  a  temperature  exceed¬ 
ing  500'^'  Fahrenheit,  the  conductmg  medium  differs  from 
those  which  require  a  higher  temperature.  In  the  lower 
portion  of  the  copper  sterii  in  which  rests  the  bulb,  the 
latter  is  immersed  in  a  mercury  bath,  which  instan¬ 
taneously  transmits  the  slightest  variation  in  temperature 
to  the  mercury  within  the  bulb,  indicating  the  circum¬ 
stance  simultaneously  on  the  scale.  The  bath  system 
insures  great  durability  to  the  thermometer,  as  the  glass 
bulb  and  tube  never  come  into  contact  with  the  hot 
liquids.  In  the  application  of  temperature  ranging  from 
100°  to  500°  Fahrenheit  this  form  of  thermometer  is  most 
superior,  being  unexceptional  from  any  standpoint. 
The  manufacturers  of  this  form  of  thermometer  have 
also,  for  higher  temperatures,  an  instrument  which  is 
unique  and  without  a  compeer  in  its  line,  the  scale  reach¬ 
ing  850°  Fahrenheit,  to  which  point  the  temperatures  of 
gases  or  liquids  are  accurately  indicated,  while  it  is  the 
ultimate  intent  of  the  makers  to  increase  the  scale  to 
1,000°  Fahrenheit.  This  thermometer  has  been  subjected 
to  protracted  and  continuous  use  at  temperatures  rang¬ 
ing  between  700°  and  850°  Fahrenheit,  at  the  end  of 
which  time  the  variation  was  insignificant,  as  demon¬ 
strated  by  a  careful  test.  When  it  is  recognized  that  the 
temperature  which  this  thermometer  is  capable  of  indi¬ 
cating  is  largely  in  excess  of  the  mercury  boiling  point, 
together  with  the  fact  that  the  fluid  metal,  when  sub- 


THE  MANUFACTURE  OF  LINSEED  OIL. 


87 


jected  to  a  heat  equivalent  to  680°  Fahrenheit,  boils  and 
is  converted  into  vapor,  the  achievement  attained  will 
be  more  fully  appreciated.  The  ebullition  of  the  mer¬ 
cury  is  obviated  by  means  of  nitrogen  gas,  its  method  of 
application  and  operation  being  patented.  In  this  in¬ 
stance  the  mercury  bath  is  substituted  by  copper  dust, 
specially  prepared  by  a  secret  process,  and,  as  a  conduct¬ 
ing  medium  and  protection  to  the  bulb,  is  in  all  respects 
equal  to  the  mercury  at  the  lower  temperatures.  The 
scales  or  dials,  which  are  hermetically  sealed  by  a  re¬ 
movable  glass  front,  are  slotted  and  held  in  position  at 
either  extremity  by  small  brass  screws,  thus  permitting 
their  adjustment  when  occasion  requires. 

MACHINERY  FOR  THE  TREATMENT  OF  OILS  WITH  FUL- 

ler’s  earth. 

Following  the  most  improved  method,  and  that  em¬ 
ployed  by  some  of  the  most  successful  refiners,  in  Eng¬ 
land  and  France,  the  mixing  kettles  are  now  constructed 
in  the  form  of  cylindrical  steel  tanks,  with  dished  ends, 
and  constructed  necks  at  the  top.  The  bottoms  are  made 
double,  so  as  to  provide  a  steam-jacket  for  heating;  and 
the  apparatus  is  further  provided  with  a  patent  vortex 
disc  agitating  gear,  which  effects  a  very  powerful  and 
rapid  admixture  of  fuller’s  earth  with  the  oil.  The  tank 
is  filled  to  the  underneath  part  of  the  neck  with  the  oil, 
or  fat,  to  be  treated,  previously  heated  to  a  temperature  of 
150°  to  180°  Fahrenheit.  The  temperature  is  important. 
The  vortex  mixer  is  kept  in  motion  while  the  tempera¬ 
ture  of  the  oil  is  being  adjusted,  and  as  soon  as  it  ar¬ 
rives  at  150°,  the  fuller’s  earth  is  added,  care  being  taken 
that  the  proper  quantity  is  employed.  It  should  be 
ground  to  a  VERY  FINE  POWDER  (we  can  refer 
prospective  purchasers  to  reliable  New  York  houses  who 
hold  in  stock  specially  prepared  material  for  this  pur- 


88 


THE  MANUFACTURE  OF  LINSEED  OIL. 


pose)  and  ought  to  be  quite  dry  and  free  from  moisture. 
This  is  most  important.  Three  to  five  per  cent  is  the 
amount  generally  used,  but,  of  course,  the  quantity  would 
depend  on  the  amount  of  color  to  be  extracted.  This 
the  refiner  can  test  by  experiment,  by  heating  a  small 
quantity  and  filtering  it  through  filtering  paper  in  a 
heated  tin  funnel  before  commencing. 

When  treating  oils  or  lard  which  are  to  be  used  as 
food,  it  is  very  important  to  remove  the  fuller’s  earth 
from  them  as  quickly  as  possible  after  the  mixing,  and 
also  that  the  mixing  should  be  effected  as  rapidly  and 
thoroughly  as  possible.  For  this  reason,  and  so  as  to 
keep  up  a  constant  supply  of  the  oils  and  fats  and  keep 
the  filter  at  work,  it  is  preferred  to  have  the  kettles 
worked  in  pairs  on  the  twin  system,  i.  e.,  whilst  one  kettle 
is  being  used  to  feed  the  oil  filters,  the  other  is  being  pre¬ 
pared  and  treated  with  fuller’s  earth. 

If  the  fuller’s  earth  remains  any  length  of  time,  say 
over  fifteen  minutes,  it  commences  to  impart  a  taste  to 
the  oil  or  lard,  and  is  objectionable.  Such  oils,  etc., 
should  be  kept  at  a  lower  temperature.  The  best  tem¬ 
perature  to  employ  can  be  readily  found  by  experiment. 

After  the  proper  quantity  of  fuller’s  earth  is  thoroughly 
mixed,  the  whole  of  the  contents  of  the  mixer  are 
pumped  by  a  steam  pumping  engine  into  the  filter  press. 
It  should  be  noted  that  kettles  made  to  hold  very  large 
quantities  are  objectionable,  as  the  fuller’s  earth  remains 
too  long  in  mixture  with  the  oil,  and  imparts  an  earthy 
taste  by  the  time  the  filter  is.  filled  with  cake.  The  filter 
is  so  proportioned  to  the  work  to  be  done,  as  to  have 
a  cake  that  will  not  be  quite  formed — a  hollow  cake. 
Steam  is  admitted  into  the  centre  feed  channel  of  the 
press,  and  it  finds  its  way  into  each  of  the  hollow  cakes. 
All  the  cocks  are  shut  off,  except  the  one  farthest  away 
from  the  head.  The  steam  passes  through  the  centre  of 


THE  MANUFACTURE  OF  LINSEED  OIL. 


89 


the  press,  and  first  steams  out  the  cake  next  the  follower. 
When  the  steam  has  blown  through  this  cake  so  as  to 
free  it  thoroughly  from  oil,  it  is  shut  off,  and  the  next 
one  opened;  and  so  on,  until  all  are  steamed.  When  the 
press  is  opened  to  remove  the  fuller’s  earth  it  falls  out  in 
powder  on  the  floor,  little  or  no  oil  being  left  in  it. 

In  the  case  of  some  oils,  such  as  castor  oil,  fuller’s 
earth  does  not  answer  as  well,  and  in  such  cases  finely 
powdered  animal  charcoal  or  else  wood  charcoal,  in  fine 
powder  (willow  charcoal  being  preferred)  is  used.  It  is 
important  also  that  the  temperature  should  be  raised  to 
about  150°  to  180°  in  these  cases  also;  in  fact,  the  ani¬ 
mal  or  wood  charcoal  miay  be  used  in  lieu  of  fuller’s 
earth,  the  same  precaution  as  to  dryness  and  fine  powder 
being  observed  in  these  cases. 

Care  should  be  taken  where  the  oils  are  viscid,  such 
as  castor  oil,  linseed  oil,  etc.,  that  the  room  where  the 
filter  is  situated  be  artificially  warmed,  so  that  the  whole 
mass  of  metal  in  the  filter  may  be  heated  up  to  the  tem¬ 
perature  at  which  it  is  found  best  to  work.  In  the  case 
of  linseed  oil,  this  should  not  be  less  than  90°  Fahrenheit. 
With  castor  oil  it  should  be  higher  still. 

Filters  are  also  made  with  each  of  the  plates  steam- 
jacketed,  so  that  the  contents  of  the  oil  filter  can  be  main¬ 
tained  at  any  temperature  required.  These  are  used  for 
testing  solid  fats,  such  as  wax,  paraffin,  vaseline,  etc. 


Economic  Oil  l^iliing— Practical  Hints  and  Suggestions  to  Oil 

IMillers. 


The  fundamental  principles  of  oil  milling  are  fine 
grinding  and  adequate  cooking  and  pressing. 

To  the  practical  oil  miller  it  would  appear,  needless  to 
say,  that  it  pays  handsomely  to  keep  the  rolls  in  good 
order.  That  is,  they  should  be  perfect  cylinders.  The 
writer  has  operated  a  most  excellent  lathe,  which 
automatically  grinds  and  trues  up  worn  rolls  in 
a  surprisingly  short  space  of  time,  an  emery 
wheel  *  working  on  each  side  of  the  revolving 
roll.  You  can  build  the  lathe  readily  and  at  a  low' 
cost.  May  add  that  this  system  of  grinding  precludes  the 
possibility  of  metallic  particles  floating  about,'  which  are 
so  injurious  to  human  lungs.  No  well-equipped  mill  can 
afford  to  be  without  this  valuable  machine.  .  It  will  pay 
for  itself  in  a  very  short  time. 

What  kind  of  belting  do  you  use  for  your  rolls?  If 
they  are  not  double,  they  should  be  -by  all  means. 

HEATING  OR  COOKING  THE  CRUSHED  SEED. 

Under  the  writer’s  supervision  was  constructed  a  form 
of  kettle  within  the  past  three  years,  which  is,  beyond , 
doubt,  the  most  effective  for  the  intended  purpose— 
a  thoroughly  cooked  material — that  has  ever  been  intro¬ 
duced.  They  are  now  being  put  up  in  first-class  mills. 
The  use  of  this  kettle  rendei's  it  possible  to  turn  out 
uniformly  well-cooked  charges  continuously. 

In  twelve  minutes  the  kettle  will  prepare  a  batch  ready 
for  withdrawal,  it  being  very  susceptible  to  heat.  It  con¬ 
sists  simply  of  two  jacketed  kettles,  15  inches  apart,  a 
disc  on  top,  upon  which  the  meal  from  the  rolls  is  dis¬ 
charged,  thus  making  three  bottoms. 

90 


THE  MANUFACTURE  OF  LINSEED  OIL. 


91 


They  can  be  made  of  any  desired  capacity.  Those 
referred  to  are  6  feet  inside  diameters,  6  feet 

4  inches  outside,  f  inch  and  f  inch  steel 
bottoms,  ^  and  5  1-16  inch  shells.  The  com¬ 

bination  turns  out  a  press  charge  of  twenty  cakes,  weigh¬ 
ing,  when  trimmed,  12^  pounds,  every  7^  minutes,  the^ 
agitation  being  of  a  very  superior  order.  The  jacketed 
kettle,  such  as  referred  to,  will  cost  about  $400,  the  at¬ 
tachments  being  fitted  thereto  on  the  mill  premises. 

Two  openings  at  bottom  of  each  kettle,  on  opposite 
sides,  are  made  for  the  entrance  of  live  'steam  with  the 
meal,  while  at  top  of  the  kettle  three  descending  steam  jets 
are  also  furnished,  passing  over  kettle  top  and  inserting 
themselves  into  the  upper  layer  of  meal.  The  agitation 
here  .caused  by  the  revolving  sweep  causes  a  thorough 
mixing  of  the  Steam  and  dry  heat  with  the  seeds.  In  the 
first  place  the  seed  falls  upon  the  disc,  which  is  about 
4  inches  less  in  diameter  than  the  two  other  bottoms  be¬ 
neath.  A  sweep  drops  a  certain  portion  of  crushed  seed 
continuously  over  the  entire  circular  edge  of  the  disc  to 
the  u^per  section  of  the  double  -kettle  immediately  be¬ 
neath.  -Here  it  is  again  mixed,- the  real  cooking  opera¬ 
tion  now  commencing.  The  material  falling  to  that  part 
of  the  kettle  beneath  which  is  furthest  from  the  centre, 
in  which  latter  location  a  small  hatchway  is  located,  close 
to  the  vertical  shaft,  gradually  works  its  way  by  reason 
of  the  mixing  and  agitating  process  to  the  central  dis¬ 
charge  gate  referred  to.  The  extent  of  this  opening  is 
readily  governed  by  the  operative.  The  treated  seed 
again  falls,  this  time  into  the  central  part  of  the  bottom 
kettle,  whence  it  works  its  way  downward  and  gradually 
further  from  the  centre,  where  it  falls  to  the  discharge 
gates  at  the  end  of  the  diametrical  line  beneath.  A 
most  thorough  and  perfect  mixing  and  heating  system  is 
thus  assured.  For  cottonseed  it  is  also  of  great  value. 


92 


THE  MANUFACTURE  OF  LINSEED  OIL. 


as  surplus  moisture  may  be  readily  eliminated  by  the 
great  dry  heat  which  may  be  radiated  throughout  the 
mass.  American  cottonseed,  which  at  times  contains  a 
large  percentage  of  moisture,  is  readily  cooked  to  the 
proper  consistency  in  this  manner,  the  live  steam  being 
shut  off  and  the  dry  heat  thus  disseminated. 

PRESSURE  APPLICATION. 

In  the  event  of  your  not  having  in  operation  the  latest 
system  of  pressure  application,  with  whatever  form  you 
may  now  use,  the  introduction  of  the  latest  and  most 
approved  method  referred  to  is  practicable.  By  the  in¬ 
sertion  of  a  small  steel  plug  (writer  has  a  number  on  hand) 
in  the  high-pressure  orifice,  the  new  system,  by  means  of 
which  the  pressure  is  applied  to  the  material  in  the  press 
in  such  a  gradual  manner  that  the  press  cloth  fabric  is 
capable  of  being  used  for  a  very  much  longer  period 
than  under  the  old  system.  A  minute  hole  is  perforated 
through  the  centre  of  the  plug,  which  has  the  effect  of 
obviating  the  sudden  change  from  the  low  to  high  pres¬ 
sure,  which  is  productive  of  so  much  destruction  to  the 
press  fabric  and  the  cause  of  breaks  in  the  presses. 

The  use  of  this  plug  will  keep  pressure  so  uniform  that 
even  in  a  large  mill  the  accumulator  system  does  not  be¬ 
come  necessary. 

AUTOMATIC  CHANGE  OF  PRESSURE. 

In  oil  mills,  heretofore,  it  has  been  the  custom  to  de¬ 
pend  entirely  upon  the  pressman  to  shut  off  the  low 
pressure  and  turn  on  the  high  at  a  certain  moment.  At 
times,  especially  on  the  night  watch,  the  careless  em¬ 
ployee,  rather  than  bend  his  back  to  shut  off  the  low 
and  turn  on  the  high  pressure  at  the  proper  time,  will 
allow  the  low  pressure  to  remain  on  during  the  entire 
pressure  period.  A  very  heavy  oil  percentage  is  thus 


THE  MANUFACTURE  OF  LINSEED  OIL. 


93 


left  in  the  cake  and  the  manufacturer  is  by  so  much  the 
loser. 

This  suggested  to  the  writer  the  idea  of  overcoming 
this  difficulty,  which  was  successfully  accomplished,  and 
in  the  following  manner.  It  is  now  in  use  in  a  24-press 
mill,  and  from  the  time  the  system  was  first  introduced 
three  years  ago,  it  has  given  great  satisfaction,  while  re¬ 
quiring  not  the  least  attention  at  any  time. 

It  simply  consists  of  this:  By  means  of  a  small  gear 
wheel,  which  is  between  and  affixed  to  the  upper  parts 
of  the  low  and  high  pressure  stops,  the  act  of  opening 
one  simultaneously  opens  the  other  stop.  Therefore, 
when  the  pressman  turns  on  the  low-pressure  pump  to 

start  the  press  ram,  the  high-pressure  pump  is  connected 

* 

or  turned  on  at  the  same  time.  Without  the  use  of 
another  device  this  operation  would  be  impracticable, 
'  for  the  reason  that  in  some  hydraulic  systems  the  high 
pressure  would  force  the  oil  into  the  low-pressure  pipes, 
unless  latter  were  shut  off,  thus  causing  disaster.  This 
suggested  the  idea  of  a  small  tumbling  valve  to  the 
writer.  This  small  tumbling  valve  is  placed  in  the  low- 
pressure  orifice,  and  most  effectively  shuts  off  the  low- 
pressure  system  when  the  high-pressure  in  its  ascent  ex¬ 
ceeds  the  latter. 

To  be  more  explicit,  this  small  tumbling  or  retaining 
valve  is  placed  right  beneath  the  low-pressure  stop  in  the 
reversing  chest.  Let  us  suppose  the  press  is  charged 
and  ready  to  ascend.  The  pressman  opens  the  stop. 
The  moment  the  pressure  exerted  by  the  high-pressure 
pump  exceeds  that  of  the  low-pressure  pump,  which 
takes  place  an  instant  or  two  after  the  oil  commences  to 
flow,  the  retaining  valve  is  forced  into  the  low  pressure 
orifice,  thus  completely  closing  off  that  system,  auto¬ 
matically,  and  in  the  most  complete  manner  possible. 
You  are  not  depending  upon  the  pressman  to  do  this. 


94 


THE  MANUFACTURE  OF  LINSEED  OIL. 


and  all  that  he  does  is  to  shut  off  the  pressure  when  the 
full  pressure  period  has  expired,  open  the  lever  and  the 
ram  descends.  This  is  a  most  excellent  system,  and  can 
be  introduced  for  a  mere  trifle. 

Have  you  in  operation  an  automatic  announcer  in 
your  mill  which  notifies  the  pressmen  when  to  charge 
their  presses  while  registering  the  work  done,  so  that  at 
any  time  during  the  week  you  can  learn  exactly  how 
many  pressings  have  been  made/ 

BOILING  BY  STEAM. 

The  steam-boiled  oil  has  a  very  large  consumption 
in  the  United  States.  A  mixing  of  2,000  gallons  is 
boiled  at  a  time,  the  steam-jacketed  kettle  hay¬ 
ing  a  capacity  of  2,500  gallons.  •  The  system  of 
mixing  is  most  perfect.  A  rotary  pump  placed 
close  to  the  kettle  is  continuously  and  rapidly 
withdrawing  the  treated  oil  from  bottom  part  of  the 
kettle  and  discharging  it  at  the.  top,  thus  obtaining  a  sys¬ 
tem  of  mixing  which  cannot  be  equaled.  The  liquid 
drier  is  most  thoroughly  mixed  and  incorporated  with' 
the  oil  and  very  excellent  results  are  obtaine*d,  all  other 
conditions  being  correct.  Air  is  also  blown 'into  the  oil 
and  maintained  during  the  operation. 

LIQUID  DRIER  MAKING- FOR  ST^AM-BOILED  OIL. 

Into  a  small  kettle,  or  iron  pot  of  suitable  capacity,  of, 
say  about  100  gallons,  put  in  48  gallons  raw  oil.  When 
250°  F.  has  been  reached,  add  under 'constant  stirring’60 
pounds  manganese,  10  pounds  sugar  of  lead,  6  pounds 
borax  and  3  pounds  of  sulphate  of  zinc.  All  must  be  added 
very  slowly,  and  to  be  constantly  agitated  and  mixed 
by  two  persons,  one  on  each  side  of  the  kettle,  furnished 
with  long  stirrers.  Heat  is  increased  to  500°,  the  agita¬ 
tion  being  maintained  unrelaxed  until  the  entire  opera- 


THE  MANUFACTURE  OF  LINSEED  OIL. 


95 


tion  is  completed,  the  stirrers  being  alternately  passed 
along  the  bottom  of  the  kettle  so  as  to  prevent  the  chemi¬ 
cals  from  settling  and  facilitate  their  incorporation  with 
the  oil. 

The  chemicals  must  be  added  a  little  at  a  time,  and, 
as  already  stated,  the  agitation  must  be  continued  until 
the  fire  is  withdrawn. 

At  any  time,  when  the  preparation  threatens  to  rise 
in  the  kettle,  pour  in  a  pail  of  raw  oil.  Raw  oil  to  the 
extent  of  30  gallons  must  be  poured  in  during  the  op¬ 
eration.  making  78  gallons  of  raw  oil  in  all. 

The  temperature  of  500°  must  be  maintained  in  the 
preparation  for  3|  hours.  • 

Twenty-eight  gallons  of  this  drier,  suitably  thinned 
with  raw  oil,  will  be  needed  for  2,000  gallons  of  oil  by  the 
steam-h-eating  or  boiling  process. 

FIRE-BOILING  SYSTEM.  ’ 

This  boiling  may  be  accomplished  in  a  casting  of  any 
desired  capacity.  We  will  suppose  the  boiling  to  con¬ 
sist  of  750  gallons  of  oil,  the  casting  or  kettle  for  which 
should  have  the  capacity  of,  say,  1,000  gallons.  When 
the  furnace  heat  has  sent  the  temperature  in  the  oil  up 
to  250°  F.,  30  pounds  of  litharge  and  10  pounds  of  umber 
are  added.  From  the  moment  the  fire  is  started  a  verti¬ 
cal  shaft,  which  runs  down  the  centre  of  the  kettle,  with 
arms  attached  with  suitable  sweep  at  bottom,  is  set  in 
motion  and  continued  until  one  hour  after  the  fire  is 
withdrawn.  A  temperature  of  475°  is  maintained  in  the 
oil  for  three  hours. 

The  resultant  product  is  a  most  excellent  boiled  oil 
drying,  with  a  rich  gloss  and  varnish-like  surface,  in  5 
or  6 'hours.  The  pot  or  kettle  is  built  up  by  masonry 
and  suitably  covered,  the  vapors  being  carried  oft’  by  a 
large  pipe  to  the  boiler  chimney. 


96 


THE  MANUFACTURE  OF  LINSEED  OIL. 


The  element  of  danger  inseparable  from  this  system  of 
fire-boiling  has  tended  to  increase  the  steam-boiling  sys¬ 
tem  with  regard  to  the  amount  of  oil  turned  out. 

TREATMENT  OF  CALCUTTA  SEED  OIL  FOR  VARNISH. 

Several  of  the  leading  crushers  make  a  specialty 
of  this  oil,  and  there  is  a  very  large  demand  for  it  from 
varnish  makers.  But  the  fact  is,  that  in  some  instances, 
it  is  composed  to  a  ver}'^  large  extent,  probably  one- 
third  of  the  whole,  of  common  American  raw. 

It  will  stand  the  fire  and  water  test  without  breaking, 
and  present  the  natural  aspect  of  well-settled  oil.  The 
method  of  procedure  is  as  follows:  Seven  quarts  of  sul¬ 
phuric  acid  are  measured  into  a  lead-lined  tub,  then  56 
quarts  of  water  are  added  to  the  acid,  the  latter  being 
66°  B. 

The  mixture  of  acid  and  water  is  now  allowed  to  stand 

•> 

over  night. 

The  treating  tank  must  be  ready,  and  in  this  case  2,800 
gallons  of  oil  are  treated  at  a  time  in  each  tank,  and  six 
tanks  of  oil  under  treatment  at  one  time.  The  air-pump 
is  started  and  the  oil  is  set  in  commotion  at  once. 
Across  the  top  of  the  tank  there  are  three  small  wooden 
runways,  upon  which  stone  jars  are  placed.  To  these 
jars  are  secured  a  long  wooden  handle,  or  stick,  by  means 
of  which  the  refiner  can  push  the  jars  with  their  contents 
backward  and  forward  over  the  top  of  the  tank  at  pleas¬ 
ure. 

In  the  jars,  three  in  number,  the  acid  and  water,  mixed 
the  previous  day,  are  poured  in.  At  the  bottom  of  each 
jar  a  small  hole,  which  has  been  carefully  drilled  through 
previously,  permits  the  solution  to  fall  into  the  agitated 
oil  beneath  in  minute  streams. 

This  has  the  effect  of  causing  the  acid  and  water  to  be 
associated  with  every  portion  of  the  mass  of  agitated  oil 


THE  MANUFACTURE  OF  LINSEED  OIL. 


97 


beneath.  When  the  oil  has  been  in  agitation  for  three- 
quarters  of  an  hour  1,500  or  1,600  gallons  of  hot  water, 
preferably  sea  water,  which  must  be  ready,  are  run  into 
the  2,800  gallons  of  oil  under  treatment. 

The  water  should  be  heated  in  an  elevated  tub  or  vat 
with  direct  steam  connection  with  the  boilers.  When 
the  water  is  all  in  the  treating  tank  the  temperature  of 
the  oil  and  water  should  be  about  130°  F.  From  the  mo¬ 
ment  the  air-pump  is  first  started,  prior  to  the  addition  of 
the  sulphuric  acid  dilution,  two  hours’  agitation  should 
intermittently  be  maintained. 

The  air  is  forced  through  a  lead  pipe  coiled  in  cir¬ 
cular  form  around  the  bottom  of  the  tank,  with  perfora¬ 
tions  closely  together  on  the  upper  end  of  same  and  the 
end  closed. 

The  preparation  is  now  left  to  repose,  and  on  the  third 
day  it  is  pumped  into  a  large  jacketed  kettle  and  dried 
by  heat,  so  that  the  moisture  will  be  thoroughly  elimi¬ 
nated.  This  usually  takes  four  hours,  but  sometimes  to 
procure  the  correct  color  it  will  take  longer. 

The  air  pump  is  operate’d  in  conjunction  with  the  dry¬ 
ing  by  heat,  and  the  oil  is  pumped  from  bottom  to  top 
continuously  by  rotary  pump  as  already  shown.  Tem¬ 
perature  should  be  about  170°  F.  When  the  oil  has  been 
properly  dried  and  aired  it  is  pumped  into  a  large  tank 
temporarily,  from  which  it  is  afterward  slowly  filtered 
and  finally  placed  in  stock  ready  for  delivery.  The  per¬ 
centage  of  water  in  this  system  is  so  small  that  it  does 
not  exceed  one  per  cent.  Filtration  makes  it  a  beautiful 
bright  oil. 

METHOD  OF  REFINING. 

Here  is  an  excellent  system  as  carried  out  in  several  of 
the  leading  mills.  The  oil  has  no  equal  in  America,  and  it 
commands  a  ready  sale.  Two  thousand  eight  hundred  gal- 


98 


THE  MANUFACTURE  OF  LINSEED  OIL. 


Ions  of  oil  are  awaiting  treatment  in  the  tank,  and  the  air 
is  turned  on,  causing  the  oil  to  be  in  commotion  at  once. 
In  three  jars  placed  over  the  top  of  the  tank  on  the 
wooden  runways  28-|  gallons  of  sulphuric  acid,  66°  B,  is 
poured.  The  acid  runs  out  in  minute  streams  and  be¬ 
comes  thoroughly  mixed  with  the  agitated  oil  beneath. 
In  this  mode  of  introduction  the  acid  will  not  char  the 
oil,  which  it  comes  in  contact  with,  which,  under  other 
conditions,  it  would  do.  It  should  take  20  minutes  for- 
the  acid  to  run  in. 

When  all  the  acid  is  in  1,500  or  1,600  gallons  of  cold 
water,  preferably  salt  or  sea  water,  is  at  once  run  in. 

The  air  agitation  is  kept  up  for  one  hour,  at  the  expira¬ 
tion  of  which  the  cold  w'ater  is  run  in,  and  the  agitation 
is  now  continued  for  three  hours  longer. 

The  oil  and  water  are  now  allowed  to  settle  for  two 
weeks  at  least,  the  longer  the  better.  It  is  then  with¬ 
drawn,  a  thousand  gallons  at  a  time,  and  steamed  in  a 
copper-lined  tank.  It  is  steamed  for  six  hours.  The 
following  day  the  water  is  drawn  off  and  the  succeed¬ 
ing  day  it  is  pumped  into  storage  tanks  to  be  delivered. 

EXTRA  REFINED  OIL,  AND  FOR  WHICH  A  FANCY  PRICE  IS 

OBTAINED. 

The  same  operations  are  pursued  as  in  the  foregoing 
process  until  the  steaming  is  executed. 

In  this  instance,  after  the  steaming  and  proper  settling 
period  have  transpired,  the  oil  is  pumped  into  a  shallow 
tank  (copper)  immediately  beneath  a  large  glass  roof, 
where  the  sunlight  may  have  unobstructed  play 
thereon,  the  oil  depth  not  exceeding  14.  inches.  It  is 
left  here  as  long  as  possible,  a  week  at  least,  from  which 
place  it  is  caused  to  run  through  a  pipe  to  a  filter  press. 
It  is  filtered  very  slowly  and  by  gravity  only.  The  re- 


THE  MANUFACTURE  OF  LINSEED  OIL. 


99 


sultant  oil  is  perfectly  bleached ;  it  is  water  white,  and  its 
brightness  is  remarkable. 

The  cost  of  a  refining  plant  is  not  great.  Two 
large  vats,  one  for  mixing  and  agitating  the  oil  and  the 
acid  and  water,  and  the  other  for  steaming,  both  being 
lead  lined. 

CAKE- PACKING  MACHINE. 

This  machine  is  a  most  useful  adjunct  to  a  mill  which 
exports  its  cake.  It  will  pack  400  or  500  bags  of  cake 
in  a  day.  The  workman  simply  fills  the  bag  with  enough 
cake  to  make  the  bag  stand.  The  bag  with  the  loosely 
put  in  cake  is  now  trucked  into  the  machine.  The  ma¬ 
chine  operative,  seizing  two  cakes,  inserts  the  lower  ends 
between  the  tops  of  the  cakes  in  the  bag  and  the  upper 
ends  are  pushed  back  until  they  stand  vertically.  The 
ram  or  arm  of  the  cake-packing  machine  is  now  caused 
to  descend,  and,  in  a  quicker  time  than  it  can  be  told,  it 
presses  the  two  cakes  clear  down  into  position  and  again 
comes  down  to  press  two  more  cakes  and  repeated  until 
the  bag  is  packed.  It  will  not  break  the  cakes  if  man¬ 
aged  as  instructed,  and  no  cake  chips  or  fragments  strew 
the  packing-room  floor,  everything  being  clean.  The 
bags  are  packed  firmly. 

The  gear  shaft  is  2|  inches  diameter  and  7  feet  2| 
inches  from  the  floor.  The  arm  extends  about  14  inches, 
and  is  secured  to  a  movable  rack  running  in  a  slot  in  an 
upright  hardware  beam  or  stout  stick.  The  iron  arm 
has  a  face  large  enough  to  drive  two  cakes.  It  should 
be  flanged.  The  small  gear  wheel  for  running  the  rack 
should  be  6  inches  in  diameter,  teeth  1  inch;  rack  54 
inches  long  by  2  inches  wide  and  speed  of  the  pulley  66 
revolutions. 

A  system  of  oil  drawing  from  storage  tanks  for  deliv¬ 
ery,  which  is  valuable,  is  deserving  of  notice.  By  sim- 


100 


THE  MANUFACTURE  OF  LINSEED  OIl! 


ply  turning  a  cock  the  oil  flows  from  the  desired  tank, 
without  belt  changing  or  starting  the  pump.  A  rotary 
pump,  always  in  operation,  together  with  a  simple  con¬ 
trivance,  produces  the  convenience  referred  to.  Boiled, 
raw,  refined  or  varnish  oil  can  be  drawn  instantly 
from  the  various  tanks'  concurrently  or  separately.  The 
use  of  this  system  is  a  very  great  convenience,  its  intro¬ 
duction  or  cost  of  same  being  unimportant. 

CAKE  TESTING. 

The  method  of  analyzing  cake  is  as  follows:  In  a  mill 
of  large  capacity  it  is  customary  to  select  a  cake  from 
each  set  of  presses  for  each  watch  of  analysis.  A  cake 
may  be  selected  from  each  press,  or  more  than  one  from 
each  other,  if  desired.  The  apparatus  needful  is  simple 
and  inexpensive,  comprising  glass  tubes  and  porcelain 
dishes  sufficient  for  each  test  of  meal  made;  a  pestle  and 
mortar,  fine  screen  and  balance  complete  the  outfit,  the 
solvent  used  being  bisulphide  of  carbon.  A  small  wooden 
stand  will  be  needed  to  hold  tubes  in  a  vertical  position, 
with  perforations  in  lower  cross-piece  to  permit  the 
pointed  ends  to  be  inserted  therein,  so  that  the  solvent 
and  oil  may  drop  unobstructedly  into  the  small  recepta¬ 
cle  beneath.  Take  the  cake  to  be  tested  and  saw 
through  diagonally,  the  fine  meal  and  fragments  falling 
on  a  previously  spread  out  paper.  Avoid  passing  the 
saw  through  the  oily  edges  of  an  imperfectly  trimmed 
cake.  This  is  accomplished  by  breaking  off  one  or  two 
inches  from  each  end.  Raise  the  meal  dust  and  cake 
fragments  and  pass  through  a  fine  screen.  The  frag¬ 
ments  may  be  reduced  by  the  pestle  and  mortar  to  a 
mealy  consistency,  the  finer  portion  being  secured  as  be¬ 
fore.  Lumpy  matter  or  fragments,  however  small,  must 
not  be  permitted  in  the  meal  to  be  tested,  and  as  an  ad¬ 
ditionally  precautionary  measure  the  pestle  and  mortar 


THE  MANUFACTURE  OF  LINSEED  OIL. 


101 


are  again  brought  into  requisition,  and  the  meal  pulver¬ 
ized  into  an  impalpable  powder.  Five  grams  of  meal 
are  now  carefully  weighed  by  the  balance,  the  weighing 
being  conducted  with  delicacy  and  exactness,  so  that  re¬ 
sults  will  be  accurate. 

The  tube  or  tubes  are  in  readiness,  each  having  a  small 
piece  of  cotton  pressed  firmly  to  the  bottom.  By  means 
of  a  small  tin  or  glass  funnel,  which  is  inserted  into  the 
upper  part  of  the  tube  to  be  charged,  the  weighed  meal 
is  now  introduced,  over  which  another  small  piece  of  cot¬ 
ton  is  pressed  down,  the  whole  being  subjected  to  a  mod¬ 
erate  strain  to  secure  compactness.  When  removing 
the  meal  from  balance  dish  to  the  tube,  carefully  dis¬ 
place  from  same  adhering  particles,  or  dusty  matter 
which  remains  on  sides  and  bottom  when  the  dish 
has  been  inverted.  This  may  be  done  with  the  cotton, 
which  is  intended  to  press  over  the  'meal,  the  funnel  being 
carefully  cleaned  down  with  same  and  the  whole  pressed 
into  position.  A  small  wire  rod  and  wooden  pin,  the 
latter  made  of  a  suitable  diameter  to  enter  the  tube,  will 
be  found  useful  adjuncts  in  this  connection. 

The  small  porcelain  dish  is  now  placed  immediately 
under  the  charged  tube  and  the  solvent  poured  in.  The 
same  funnel  which  introduced  the  meal  will  answer  this 
purpose,  when  the  top  is  closed  with  a  small  piece  of 
cotton.  The  bisulphide  of  carbon  will  be  observed  pass¬ 
ing  through  the  compressed  meal  and  a  few  minutes 
later  falling  into  the  dish  beneath,  together  with  the  oil. 
The  bisulphide  of  carbon  is  added  in  the  following  man¬ 
ner:  To  place  this  phase  of  the  testing  operation  before 
the  prospective  analyst  in  the  most  simple  manner  it 
will  be  necessary  to  give  the  dimensions  of  the  glass 
tubes,  which,  for  other  reasons,  it  is  also  essential  to  ex¬ 
plain. 

I'he  tube  should  be  about  15  inches  long  and  one-half 


102 


THE  MANUFACTURE  OF  LINSEED  OIL. 


inch  wide  and  blown  to  a  point  at  one  end.  Bisulphide 
of  carbon  sufficient  to  occupy  6  inches  of  the  tube  space 
will  suffice  for  the  first  charge,  when,  at  the  expiration  of 
two  or  three  hours,  about  2  inches  more  are  poured  in, 
and  in  an  hour  or  so  afterward  the  final  addition  is  made 
— about  1  inch.  A  good  plan  is  to  have  this  accom¬ 
plished  late  in  the  day,  allowing  the  solvent  and  oil  to  re¬ 
main  over  night,  when  the  former  will  have  been  almost 
completely  evaporated.  However,  this  is  not  essential, 
as  when  the  last  charge  of  solvent  has  percolated  through 
the  meal,  the  small  dishes  may  be  placed  over  a  heater 
or  stove,  when  the  solvent  or  moisture  that  may  be  pres¬ 
ent  is  removed  with  facility,  leaving  the  pure  cotton  oil 
in  readiness  for  weighing. 

Under  any  circumstances  it  is  necessary  to  place  the 
dishes  with  their  contents  on  the  heater  or  stove,  so  that 
possible  traces  of  solvent  or  moisture  may  be  assuredly 
eliminated.  The  dish  and  oil  are  now  weighed  and  the 
result  jotted  down,  the  oil  is  carefully  wiped  out,  the 
weight  of  the  empty  dish  ascertained,  which,  deducted 
from  the  original  figures  or  gross  weight,  gives  the  exact 
percentage  of  the  oil  left  unextracted  by  hydraulic  pres¬ 
sure.  A  good  plan  is  to  have  the  weight  of  the  empty 
dish  beforehand,  a  distinguishing  mark,  or  number,  still 
further  simplifying  matters.  Of  the  5,000  grams  of  meal 
we  will  say  for  illustration  430  grams  of  oil  are  obtained 
or  equal  to  8.6  per  cent  of  the  weight  of  the  meal,  which 
is  the  exact  percentage  of  oil  left  in  the  cake. 

The  wooden  stand  or  stands  may  be  made  of  sufficient 
capacity  to  hold  6,  12  or  20  tubes,  or  as  many  as  will  be 
required  for  a  regular  testing  operation,  according  to 
mill  capacity.  A  record  book  should  be  kept  show¬ 
ing  results,  which  may  be  referred  to  for  purposes  of 
comparison  at  any  time.  The  method  is  simple  and  ab¬ 
solutely  accurate,  the  last  vestige  of  the  oil  being  effect- 


THE  MANUFACTURE  OF  LINSEED  OIL. 


103 


ively  withdrawn  from  the  meal.  In  this  connection 
ether  is  generally  supposed  to  be  a  more  powerful  and 
effective  solvent,  but  by  following  the  particulars  here 
laid  down  a  much  more  simple  and  practicable  factory 
method  will  be  secured,  while  being  uniformly  reliable. 
Bisulphide  of  carbon  may  be  purchased  at  9  or  10  cents 
per  pound,  while  there  is  many  times  this  price.  A  pound 
of  bisulphide  will  suffice  for  12  or  14  tests. 

One  point  should  always  be  borne  in  mind.  Bisul¬ 
phide  of  carbon  is  extremely  inflammable;  its  vapor,  even 
when  confined,  is  explosive.  No  light  or  fire  should  be 
brought  into  its  vicinity.  With  care  in  this  respect,  how¬ 
ever,  it  is  easy  and  safe  to  handle,  and  it  is  not  dangerous 
to  inhale  a  reasonable  amount  of  the  vapor,  in  spite  of 
its  offensive  odor,  to  which,  by  the  way,  one  soon  be¬ 
comes  accustomed. 

The  writer  has  used  this  system  regularly  for  twelve 
years  in  preference  to  all  others  and  with  uniform  satis¬ 
faction. 

EXTRACTION  OF  OIL  WITH  ETHER. 

In  most  factories  working  on  a  large  scale  with  bi¬ 
sulphide  of  carbon,  experiments  on  a  small  scale  are  gen¬ 
erally  made  with  ether. 

It  has  been  shown  by  numerous  experiments  that  the 
seed  is  completely  exhausted  with  ether,  and  the  oil 
after  evaporation  is  of  excellent  quality.  But,  notwith¬ 
standing  that  the  advantages  of  ether  over  bisulphide  of 
carbon  and  canadol  are  known,  its  use  on  a  large  scale 
never  proved  a  success. 

The  loss  by  evaporation  in  an  incompletely  closed  ap¬ 
paratus  was  feared,  and  the  use  of  water,  as  with  bisul¬ 
phide  of  carbon,  was  not  possible,  the  specific  gravity  of 
bisulphide  of  carbon  being  127,  and  that  of  ether  only 
.072.8.  Consequently  the  latter  would  not  sink  in  water. 


104 


THE  MANUFACTURE  OF  LINSEED  OIL. 


Very  recently  O.  Braun  has  proposed  the  extraction 
of  seed  oil  on  a  large  scale  by  ether.  It  is  claimed  that 
the  properties  of  ether,  as  well  as  its  low  specific  gravity 
and  low  boiling  point,  are  not  hurtful  but  rather  ben¬ 
eficial  in  an  entirely  closed  vessel  or  apparatus. 

On  account  of  the  low  specific  gravity  one  pound  of 
ether  occupies  nearly  double  the  space  of  one  pound  of 
bisulphide  of  carbon,  and  as  the  solvents  are  used  by 
measure  and  not  by  weight,  the  difference  in  price  is  al¬ 
most  annulled. 

The  low  boiling  point  allows  of  a  rapid  and  complete 
distillation  of  the  ether  from  the  oil  and  the  residue. 
(Braun’s  work.) 

Extractors  3^  feet  high  and  feet  wide,  550  pounds 
capacity  of  crushed  seed  and  in  40  minutes  the  process 
is  complete,  and  the  last  vestige  of  ether  odors  removed 
by  steam,  driving  the  ether  into  the  distilling  vessel. 
The  consumption  of  ether,  it  is  claimed,  does  not  exceed 
one  per  cent  of  the  oil  extracted. 

AUTOMATIC  CHANGING  FROM  LOW  TO  HIGH  PRESSURE — 
HOW  TO  FACILITATE  THE  MAXIMUM  OIL  YIELD 
WHILE  SAVING  THE  PRESS  CLOTH. 

The  automatic  change  from  low  to  high  pressure 
without  breaking  into  the  hydraulic  pipes  was  success¬ 
fully  experimented  upon  by  the  writer  in  1891,  and  is  now 
in  regular  operation. 

By  means  of  a  small  tumbling  or  retaining  valve  placed 
in  the  low-pressure  orifice  in  reversing  chest,  right  under 
the  screw  stop-cock,  the  seat  must  be  trued  up,  so  that 
when  the  upper  part  of  the  retaining  valve  receives  the 
pressure  from  the  high-pressure  pump,  no  oil  can  pass 
around  or  beneath  it.  Let  us  suppose  the  press  is 
charged  and  ready  to  ascend;  the  two  stops,  high  and  low, 
must  be  swung  wide  open;  the  ram  then  ascends.  The 


THE  MANUFACTURE  OF  LINSEED  OIL. 


105 


moment  the  pressure  exerted  by  the  high-pressure  pump 
exceeds  that  of  the  low-pressure  pump,  the  retaining 
valve  is  driven  into  its  seat,  as  the  pressure  strikes  the 
head  of  the  retaining  valve  equally  with  any  part  of  the 
ram,  thus  stopping  the  pressure  from  going  below  it. 
When  the  time  has  arrived  for  emptying  the  press  the 
two  stops  are  shut,  the  relief  valve  opened  and  ram  de¬ 
scends. 

The  uniformly  good  results  obtained  from  running 
the  mill  on  above  principle  would  be  difficult  to  over¬ 
estimate,  as  compared  with  old  principles.  The  small 
plug  in  the  high-pressure  orifice  and  retaining  valve  in 
the  low-pressure  orifice  make  this  a  beautiful  piece  of 
work.  The  small  plug  prevents  the  pressure  from  com¬ 
ing  too  suddenly  on  the  bags  in  presses,  causing  the  pres¬ 
sure  to  slowly  and  gradually  increase,  a  saving  of  25  per 
cent,  and  saving  very  considerably  in  press  bag¬ 
ging.  The  retaining  valve  insures  the  full  length  of  time 
under  high-pressure  “nip”  without  depending  on  the 
pressman,  who  at  times  neglects  to  make  the  change, 
which  causes  a  high  percentage  of  oil  to  go  off  in  the 
cake  nearly  all  the  time.  The  uniform  good  yield  of  the 
mill  since  the  above  principles  were  put  in  regular  opera¬ 
tion  bears  undoubted  testimony  to  the  fact.  The  high 
pressure  now  being  regulated  by  the  small  plug  with  the 
No.  12  core  also  prevents  the  meal  from  being  squeezed 
out  from  between  plates  on  each  side  of  the  press,  causing 
it  to  run  down  and  fill  up  the  troughs  below  every  few  days. 
F  ormerly  the  troughs  under  the  presses  were  cleaned  out 
twice  a  week;  now  they  are  cleaned  once  in  two  weeks. 
On  old  principles  the  pressure  coming  suddenly  on  bags 
and  meal  ripped  and  burst  the  former  and  caused  the  lat¬ 
ter  to  rush  out,  filling  troughs  and  causing  lots  of  work 
in  the  pressroom.  The  percentage  was  regularly  from 
8  to  10  per  cent,  many  times  up  to  11  or  12  per  cent. 


106 


THE  MANUFACTURE  OF  LINSEED  OIL. 


Before  this  important  change  was  made  in  the  mill  re¬ 
ferred  to  the  general  average  was  about  9  to  9^  per  cent. 
It  was  thus  brought  down  to  6  per  cent,  and  it  rarely 
reached  7  per  cent,  the  general  average  being  in  the 
neighborhood  of  6^  to  6f  per  cent. 

The  percentage  of  oil  left  in  cake  is  always  less  in  Cal¬ 
cutta  seed  than  in  American. 

METHOD  OF  ANALYZING  CALCUTTA  SEED  BY  WEIGHT. 

The  following  explanation  supposes  the  use  of  the 
Marseilles  system  of  sieves,  which  are  in  number  from  1 
to  6  inclusive,  being  placed  over  each  other: 

To  weigh  an  average  sample  of,  say,  100  grams,  pass 
from  No.  5  sieve  about  9-10  of  this.  That  remaining  will 
mostly  contain  large  non-oleaginous  matter  mixed  with 
linseed,  etc.  Separate  this  into  two  parts;  the  non- 
oleaginous  lay  aside,  the  remainder  re-mix  with  seed 
now  in  sieve  No.  3.  Work  the  seed  in  No.  3  lightly 
with  the  hand  for  a  short  time,  when  it  will  be  found  con¬ 
siderably  smaller  oil  seed,  and  dust  will  enter  into  No. 
2.  Rub  the  contents  of  No.  2  and  afterward  No.  1  with 
wash  leather  in  order  to  crush  into  dust  the  non-oleagi¬ 
nous  matter,  returning  to  and  re-mix  in  each  case  with 
the  linseed  now  in  No.  3  the  oleaginous  and  non-oleagi¬ 
nous  too  large  to  pass  through  Nos.  1  and  2. 

First  dust: 

The  fine  dust  now  formed  to  be  added  to  that  first  sepa¬ 
rated  from  No.  5,  which  together  constitute  the  first  dust 
to  be  afterward  weighed  and  percentage  taken.  Of  the 
seed  cleaned  from  the  first  dust,  take  an  average  sample 
by  weight  of,  say,  25  grams,  separate  in  three  parts, 
namely,  linseed,  oleaginous  matter,  other  than  linseed 
and  non-oleaginous  matter. 

Second  dust: 

This  last  dust  is  called  the  second  dust,  in  order  to 


THE  MANUFACTURE  OF  LINSEED  OIL. 


107 


arrive  at  a  percentage  or  per  cent  of  second  dust  to 
first,  obtained  for  total  non-oleaginous  matter  ad¬ 
mixture.  In  the  same  way  obtain  the  percentage  of 
oleaginous  admixture  in  the  25  grams  taken,  which  must 
be  divided  by  2,  and  is,  therefore,  assumed  as  being  one- 
half  the  value  of  linseed. 

Add  the  oleaginous  and  non-oleaginous  together. 
The  difference  between  the  total  and  4  per  cent  will  show 
the  allowance  to  be  made;  if  less  than  4  per  cent  to  the 
seller,  if  more  to  the  buyer. 

A  MORE  SIMPLE  METHOD  OF  ANALYZING  CALCUTTA  SEED. 

Weigh  100  grams  dead  fine.  Shake  up  the  seed 
well  in  a  circular  covered  tin  sieve,  divided  into  about 
six  chambers,  the  perforated  holes  in  the  top  chamber 
being  largest,  the  size  of  the  holes  decreasing  in  each 
successive  chamber  until  the  bottom  one  is  reached,  the 
bottom  of  which  is  similar  to  cover  on  top,  a  plain  tin 
surface.  The  agitation  of  the  seed  in  the  chamber  greatly 
facilitates  the  separation  of  the  dirt  and  foreign  matter 
from  the  pure  seed. 

The  oleaginous  matter  must  be  carefully  separated 
from  the  non-oleaginous  matter,  wdien  the  three  ingre¬ 
dients  must  be  accurately  weighed. 

The  result  gives  at  once  the  proportion  of  dirt  and 
foreign  matter  in  the  seed. 

When  the  oleaginous  matter  exceeds  2  grams,  no 
more  than  one  gram  is  allowed  to  be  added  as  pure  seed, 
for  instance: 

97.000— Pure 
1.000 — Oleag. 

- Non-oleag. 


97.000 

2.200 

.750 


98.000  or  2  per  cent. 


108 


THE  MANUFACTURE  OF  LINSEED  OIL. 


METHOD  OF  ANALYZING  AMERICAN  OR  EUROPEAN  SEED. 

Capacity  of  scale  must  be  one  pound,  having  two  rows 
of  graduating  figures.  The  upper  row  should  be  from  ^ 
to  16  ounces.  The  lower  row  from  .0  to  100.  The  man¬ 
ner  of  using  is  to  weigh  one  pound  of  seed  in  the  scoop,  v 
and  next  sift  in  a  double  sieve,  then  place  the  dirt  in  the 
scoop  and  the  lower  row  of  figures  will  indicate  the  per¬ 
centage  of  dirt;  or,  by  placing  the  clean  seed  in  the 
scoop,  the  percentage  of  clean  seed  will  be  ascertained. 

In  connection  with  the  scale,  the  Chicago  Board  of 
Trade  adopted  as  standard  sieves  one  having  a  mesh 
3x16  and  one  with  a  mesh  16  x  16 — Fairbanks. 

COLD-PRESSED  OIL. 

Fine  linseed  oil  is  always  obtained  by  pressing  it  at 
an  ordinary  temperature —  cold  pressing;  by  heating  the 
pressed  pulp  to  about  170°  or  180° — hot  pressing — a 
larger  percentage  of  oil  can  be  obtained,  but  it  is  always 
inferior  in  quality  to  the  cold-pressed  oil. 

Cold-pressed  oil  has  a  very  light-yellow  color,  very  lit¬ 
tle,  but  a  peculiar  taste  and  odor;  the  hot-pressed  oil 
has  a  much  darker  color,  golden-yellow  to  amber;  tastes 
much  stronger  and  more  disagreeable  than  the  former. 

CURIOUS  FACTS  CONCERNING  THE  OIL  EXTRACTED  FROM 

FOREIGN  SEEDS. 

Oil  made  from  Bombay  seed  does  not  make  good 
sweetmeats,  although  the  latter  is  unusually  clear.  This 
is  owing  to  its  excessive  fatty  properties;  it  makes  an 
excellent  refined  oil  nevertheless. 

In  the  cooking  of  a  small  quantity  of  this  class  of  oil, 
when  the  desired  rubber  consistency  was  arrived  at,  the 
loss  in  waste  equaled  35  per  cent.  The  explanation 
would  appear  to  be,  that  the  fatty  and  volatile  ingredients 
under  the  influence  of  high  temperature  disappear,  re¬ 
ducing  the  weight  of  the  whole  accordingly. 


THE  MANUFACTURE  OF  LINSEED  OIL. 


109 


A  peculiar  feature  of  the  Argentine  seed  oil  consists 
in  the  fact  that  it  also  makes  an  unprofitable  varnish  oil, 
from  the  varnish  maker’s  standpoint;  the  waste  being 
abnormal  in  its  cooking.  The  writer  tested  a  ten-pound 
lot  of  well-settled  oil,  cooking  same  3^  hours,  at  a  tem¬ 
perature  of  507°  Fahrenheit,  the  loss  being  22  per  cent. 
A  second  sample  showed  a  similar  loss,  the  finished 
sample  resembling  molasses  rather  than  the  ordinary 
linseed  oil  caoutouche.  This  class  of  seed  makes  a  very 
dark  or  dark  reddish  oil,  while  the  cake,  which  sells  read¬ 
ily  on  the  foreign  market,  is  of  a  light  color.  The  oil  may 
be  used  to  excellent  advantage  for  boiled  oil,  whether  by 
the  fire  or  steam  operation, 

LINSEED  OIL  AND  CAKE  MACHINERY, 

It  has  already  been  stated  that  in  order  to  procure  a 
really  pure  oil  the  first  important  step  in  the  manufac¬ 
turing  process  is  that  of  seed  cleaning.  There  are  ex¬ 
cellent  seed  screens  now  on  the  market,  their  cost  being 
in  the  neighborhood  of  |250,  They  perform  their  work 
effectively,  the  capacity  being  about  500  bushels  of  seed 
in  twenty-four  hours.  There  are  other  screens  of  a  much 
larger  capacity.  Where  a  fair  quality  of  seed  is  operated 
on,  the  use  of  this  machine  entirely  obviates  the  chances 
of  an  oil  showing  “fattening”  proclivities. 

It  must  be  conceded,  however,  that  the  use  of  these 
screens  is  uncommon  and  only  operated  on  special  oc¬ 
casions. 


SEED  CRUSHING  ROLLS, 

The  rolling,  or  seed-bruising,  machine  is  next  in  order, 
and  consists  usually  of  a  stack  of  chilled  iron  rolls,  the 
number  and  proportions  varying  according  to  the  nature 
and  amount  of  work  they  are  called  upon  to  perform. 
Undoubtedly  the  best  -kind  in  use  is  the  five-stack 
variety,  the  rolls  being  placed  on  top  of  each  other,  all 


no 


THE  MANUFACTURE  OF  LINSEED  OIL. 


the  shafts  excepting  those  of  the  bottom  roll  having 
boxes  accurately  fitted  to  them,  so  that  they  are  held 
firmly  in  position  by  the  strong  iron  frame  which  con¬ 
tains  them.  The  journals  of  the  bottom  roll  rest  in  brass 
bearings,  and  the  whole  machine  is  usually  operated 
by  belts.  Gearing  is  sometimes  used  to  actuate  them, 
but  it  has  not  been  found  as  economical  as  the  former. 

The  modus  operandi  is  as  follows :  Three  of  the  five  rolls 
revolve  in  one  direction,  while  the  remaining  two,  which 
are  placed  between  the  first  and  third,  and  third  and  fifth 
rolls,  respectively,  are  moved  the  reverse  way  by  fric¬ 
tion.  The  seed  from  the  hopper  first  passes  a  small  cor¬ 
rugated  feed  roll,  which  distributes  it  uniformly  over  the 
entire  length  of  the  topmost  roll,  and  by  means  of  a 
guide-plate,  it  is  directed  between  the  first  and  second 
rolls,  the  inward  motion  of  the  revolving  cylinders 
rapidly  drawing  and  crushing  the  material,  and  causing 
it  to  pass  out  on  the  opposite  side ;  here  it  is  again  guided 
by  the  slanting  position  of  a  plate  which  causes  it  to  fall 
along  the  face  of  roll  number  three  and  to  pass  between 
the  latter  and  roll  number  two,  thus  crushing  it  again 
in  its  passage  and  facilitating  the  process  by  the  weight  of 
the  two  upper  rolls.  In  a  similar  manner,  the  seed  is 
carried  through  the  lower  rolls. 

When  passing  between  the  lower  rolls,  which  termin¬ 
ates  its  winding  course  through  this  machine,  the  seed 
receives  the  added  weight  of  the  four  upper  rolls,  which 
pulverizes  it  to  a  degree  of  fineness  which  materially 
promotes  the  flow  of  oil  when  subjected  to  hydraulic 
pressure.  This  method  of  grinding  seed  is  the  most  effi¬ 
cient  ever  devised. 

The  guide-plates  also  act  as  scrapers  or  cleaners  to 
remove  the  pulpy  substance  which  sometimes  forms  on 
the  rolls’s  surfaces,  and  which,  without  the  use  of  these 
plates,  would  render  friction  abortive. 


THE  MANUFACTURE  OF  LINSEED  OIL. 


Ill 


Rolls  of  this  class  are  usttally  four  feet  long  and  from 
fourteen  to  sixteen  inches  in  diameter.  There  are  other 
rolls  smaller  in  size  and  fewer  in  number,  some  consist¬ 
ing  of  four,  some  of  three,  and  in  some  remote  localities 
the  old  method  of  operating  two  rolls  of  similar  or  dif¬ 
ferent  diameters,  bound  together  laterally,  yet  holds 
sway.  The  work  performed  by  these  is  very  inferior, 
its  efficiency  being  very  little  advanced  by  the  use  of 
stone-edge  runners,  which  usually  enter  into  the  combin¬ 
ation;  but  this  system  of  linseed  oil  milling  will  soon 
have  become  a  thing  of  the  past. 

COOKING  OR  HEATING  KETTLE. 

Next  in  order  comes  the  heating  kettle.  These  are 
usually  jacketed  throughout;  steam  pressure  is  obtained 
directly  from  the  boilers  used  for  heating  purposes. 
Small  apertures  are  tapped  in  the  side  at  various  points 
to  permit  the  entrance  of  live  steam  into  the  mass  of  meal 
in  the  kettle  in  order  to  admit  the  moisture  necessary 
to  cook  it  to  the  proper  consistency.  A  vertical  shaft 
runs  through  the  centre,  the*  arms  attached  to  which 
cause  increasing  commotion  in  the  meal,  thus  thoroughly 
mincing  all  its  parts  and  permitting  the  heat  from  the 
jacketed  sides  to  come  in  contact  with  as  much  as  pos¬ 
sible  of  the  agitated  mass.  There  are  several  forms  of 
kettles  in  use;  some  having  three  chambers;  the  ob¬ 
ject  aimed  at  in  this  design  is  to  procure  a  uniformly 
cooked  meal.  The  upper  chamber  receives  its  charge 
direct  from  the  rolls  continuously  and  gives  the  seed  a 
preliminary  treatment,  after  which,  by  the  withdrawal  of 
a  slide,  it  is  permitted  to  fall  into  the  second  chamber, 
in  which  the  cooking  operation  is  always  proceeding, 
and  when  sufficiently  treated,  is  permitted  to  fall  to  the 
lower  or  delivery  chamber.  The  latter  at  all  times  con¬ 
tains  a  charge  ready  for  withdrawal  to  the  mold  on  its 


112 


THE  MANUFACTURE  OF  LINSEED  OIL. 


passage  to  the  hydraulic  press.  There  are  other  ket¬ 
tles  consisting  of  two  chambers,  and  good  results  are 
sometimes  obtained  from  those  containing  only  one 
chamber,  conditional  upon  proper  attention  being  be¬ 
stowed  on  this  very  essential  part  of  oil  milling.  Experi¬ 
ence  has  demonstrated  that  where  more  than  one  cham¬ 
ber  is  in  use,  more  uniform  and  satisfactory  results  are 
obtained. 


CAKE  FORMER  OR  MEASURING  FRAME. 

We  now  come  to  the  cake  former  or  measuring  com¬ 
pressor.  Of  this  indispensable  machine  there  is  also  a 
variety  in  use;  but  a  description  of  one  of  the  latest  im¬ 
proved  patterns  will  suffice  for  all  practical  purposes. 

From  an  economical  point  of  view,  as  well  as  from  its 
superiority  of  design  and  its  efficiency  in  execution,  the 
hydraulic  cake  former  unquestionably  stands  in  the 
highest  rank.  Its  purpose  is  to  measure  correctly  and 
to  compress  into  convenient  and  compact  form  the 
cooked  material  from  the  heating  kettles,  so  that  it  can 
be  placed  with  facility  between  the  plates  of  the  great 
hydraulic  presses  for  the  final  process.  The  introduction 
of  the  power  and  steam  formers,  similar  in  design  to 
the  hydraulic  former,  made  possible  the  abolition  of  the 
old  box  system  in  oil  milling,  and  completely  revolu¬ 
tionized  the  cumbersome  methods  which  prevailed  some 
twelve  years  ago.  While  the  capacity  of  this  style  of 
mechanical  former  or  measuring  compressor  is  many- 
fold,  that  of  the  old  system  of  gauging  by  hand  the  quan¬ 
tity  of  crushed  seed  each  press  sack  shall  contain,  it 
also  effects  a  saving  of  from  40  to  50  per  cent  in  the  cost 
of  labor. 

The  machine  is  about  three  and  one-half  feet  in  height, 
the  head  and  base  plates  being  firmly  connected  by  three 
stout  iron  bolts,  one  at  each  angle  at  one  end  and  central 


THE  MANUFACTURE  OF  LINSEED  OIL. 


113 


at  the  other  end.  The  base  and  head  plate  form  a 
parallelogram,  and  are  about  four  feet  four  inches  in 
length. 

lo  the  underside  of  the  head  piece  is  securely  adjusted 
a  plunger.  This  is  a  projecting  block  of  iron,  the  sides 
of  which  being  beveled  to  a  point,  give  it  a  depressed 
surface  across,  so  that  when  a  cake  is  formed,  the  edges 
being  thin  and  hard,  the  meal  will  not  drop  to  the  floor 
in  its  passage  to  the  press;  the  ends  being  protected  by 
the  cloth.  The  meal  is  formed  slightly  smaller  than  the 
cake,  also  to  facilitate  its  handling.  On  the  base  plate 
rests  a  small  hydraulic  cylinder,  having  a  ram,  say,  eight 
inches  diameter,  operated  by  the  low  pressure  hydraulic 
power,  which  exerts  a  pressure  of  about  500  pounds  per 
square  inch.  This  pressure  is  uniformly  distributed  and 
forms  the  meal  into  a  compact  cake  about  one  and  one- 
half  inches  thick.  The  machine  itself  can  be  operated 
with  precision  and  despatch  at  each  pressing.  On  each 
side  of  the  cylinder  a  small  trackway  is  provided  for  the 
travel  of  the  molding  box,  which  contains  the  meal  to 
be  compressed. 

The  exact  method  of  procedure  when  the  machine  is 
in  motion  is  as  follows:  The  machine  being  at  rest,  the 
molding  box  is  in  exact  line  with  the  delivery  plate  pro¬ 
jecting  beneath  the  kettle.  Mounted  on  the  delivery  plate 
and  beneath  the  kettle  is  the  measuring  box,  open  at  the 
top  to  receive  meal  from  the  kettle  by  withdrawing  a 
slide,  and  open  at  the  bottom  to  deliver  the  meal  into 
the  molding  box.  The  flapper  frame  and  appendage  to 
facilitate  the  handling  of  the  pans  and  trays  and  cloths 
being  up,  a  tray  is  placed  in  position  in  the  molding  box, 
and  over  this  is  placed  a  cloth,  the  centre  of  the  cloth  be¬ 
ing  at  the  centre  of  the  tray.  The  flapper  frame  is  now 
brought  down,  forming  a  continuous  track  on  which  the 
measuring  box  travels.  This  box  is  mounted  on  wheels 


114 


THE  MANUFACTURE  OF  LINSEED  OIL. 


and  provided  with  scrapers,  so  that  when  it  is  drawn 
forward  and  backward  on  the  track  and  over  the  molding 
box,  the  meal  is  dropped  into  the  molding  box  and  the 
flapper  frame  and  delivery  plate  are  scraped  clean,  so 
that  the  operation  is  a  “tidy”  one.  The  measuring  box 
is  now  pushed  back  beneath  the  kettle  to  be  filled  for  the 
next  cake.  The  flapper  frame  is  raised  and  the  ends  of 
the  cloth  are  folded  over  the  top  of  the  meal,  slightly 
overlapping. 

The  entire  molding  box  with  its  load  consisting  of 
pan,  cloth  and  meal  is  pushed  forward  until  it  stops  at 
a  point  exactly  beneath  the  plunger,  on  the  under  side  of 
the  head  plate.  Pressure  is  now  turned  on;  the  cylinder 
ascends,  raising  the  molding  box  with  its  load  above 
the  trackways  and  compressing  the  material  against  the 
plunger  into  proper  shape  firmly,  and  into  its  smallest 
compass,  suitable  for  the  operation  of  pressing.  After 
a  few  seconds,  pressure  is  released,  the  cylinder  descends 
and  the  wheels  of  the  molding  box  fall  smoothly  to  the  • 
tracks;  a  perfect  cake  has  been  formed  and  the  machine 
is  again  at  rest. 

The  molding  box  is  drawn  back  until  it  stops.  The 
cake  to  be  pressed  for  oil  is  taken  up  with  its  cloth  and 
slid  between  the  plates  of  the  powerful  hydraulic  press. 
The  pan  is  now  withdrawn.  The  whole  operation  oc¬ 
cupies  only  a  small  fraction  of  the  time  required  to  de¬ 
scribe  it.  The  moment  the  loaded  pan  is  removed  from 
the  molding  box,  another  pan  is  placed  in  position  with 
a  new  cloth,  the  flapper  frame  is  brought  down  and  the 
measuring  box,  which  is  already  filled  with  another 
charge,  is  again  drawn  over  the  molding  box;  and  the 
-operation  proceeds  thus  continuously. 

This  cake  former  or  measuring  compressor  is  built 
single  or  double.  When  built  double,  for  two  operators, 
it  is  provided  with  a  simple  mechanism  which  renders 


THE  MANUFACTURE  OF  LINSEED  OIL. 


115 


the  one  operator  entirely  independent  of  the  other.  Its 
pressure  niav  be  easily  regulated,  and  it  is  adjustable  as 
to  the  weight  of  the  cake. 

Eighty  cakes  in  eight  minutes,  weighing  12|  pounds 
when  pressed,  are  molded  on  this  machine  in  routine 
work.  The  cakes  so  molded  are  the  most  perfect  that 
have  been  produced,  which  point  greatly  facilitates  their 
adjustment  in  the  hydraulic  presses,  saves  cloth,  and 
guarantees  more  oil.  In  mills  provided  with  the  accu¬ 
mulator  system  of  the  Buckeye  Brass  and  Iron  Works, 
Dayton,  Ohio,  the  low  pressure  is  utilized  to  operate  the 
cake  former,  and  in  the  absence  of  this,  suitable  pressure 
is  provided  for  its  operation 'by  a  single  plunger  power 
hydraulic  pump  and  small  accumulator. 

The  Stilwell-Bierce  &  Smith-Vaile  Co.,  of  Dayton, 
Ohio,  are  makers  of  an  excellent  cake  former  which  is 
operated  by  compressed  air.  Writer  has  seen  one  in  use 
in  a  leading  cotton  oil  mill  in  Texas,  the  superintendent 
of  the  mill  giving  the  machine  a  high  character  during 
inspection.  This  well-known  house  also  makes  a  com¬ 
plete  line  of  oil  mill  machinery,  as  does  the  Buckeye 
Brass  and  Iron  Works,  of  which  Mr.  Charles  E.  Pease 
is  president. 

PRESSURE  PUMPS. 

With  regard  to  the  steam  hydraulic  pump,  the 
Worthington  make  presents  features  deserving  of  the 
oil  miller’s  consideration. 

When  the  greatest  efficiency  is  desired  with  the  least 
consumption  of  power,  this  steam  hydraulic  pump 
may  be  used  to  advantage.  Its  first  cost  is  con¬ 
siderably  more  than  a  first-class  belt  pump,  but  it  uses  no 
steani  that  is  not  required  for  effective  work,  and  “follows 
up”  without  loss  of  power.  In  a  belt  pump  the  sur¬ 
plus  water  must  overflow  through  the  safety  valve,  con- 


116 


THE  MANUFACTURE  OF  LINSEED  OIL, 


J 


THE  MANUFACTURE  OF  LINSEED  OIL. 


117 


suming  power,  and  wearing  the  valve  rapidly.  In  run¬ 
ning  a  number  of  presses  with  an  accumulator  a  steam 
hydraulic  pump  is  particularly  desirable.  The  pump 
ends  and  plungers  are  made  of  forged  steel,  and  the 
valves  easily  accessible.  A  safety  valve  may  be  pro¬ 
vided,  and  the  whole  set  on  a  base  in  the  form  of  a 
saucer,  which  catches  any  drip  and  conducts  it  through 
a  Avater-pipe  where  desired.  Any  desired  size  can  be 
furnished. 

Realizing  the  fact  that  any  form  of  cast  metals  is  not 
safe  under  high  pressure,  unless  it  is  of  such  a  shape  that 
it  can  be  lined  with  copper  or  steel,  this  hydraulic 
pressure  pump  is  constructed  of  forgings.  Further¬ 
more,  the  pump  is  one  in  which  the  water  ends,  in- 
steadl  of  being  made  of  castings,  are  forged  solid  with  all 
openings,  plungers,  etc.,  drilled  out  of  the  solid  forgings. 
This  makes  it  absolutely  safe,  and  pumps  constructed  in 
this  way  operate  satisfactorily  at  a  pressure  up  to  10,000 
pounds  per  square  inch;  but  after  the  pressure  exceeds 
5,000  pounds  there  is  so  much  difficulty  with  the  valves, 
and  they  need  regrinding  so  often  that  the  company  does 
not  recommend  anything  higher  than  5,000  pounds 
pressure  for  ordinary  services.  This  really  is  very  much 
in  excess  of  the  pressure  which  the  oil  miller  requires, 
and,  therefore,  the  pump  referred  to  is  admirably 
adapted  for  oil  milling  purposes. 

The  accompanying  cut  will  convey  an  idea  of  the  gen¬ 
eral  outline  of  the  pump  we  have  endeavored  to  de¬ 
scribe. 


THE  HYDRAULIC  PRESS, 

In  the  complex  system  of  machinery  indispensable  to 
oil  milling,  to  the  hydraulic  press  must  be  assigned  a 
most  essential  part.  Here  the  manufacturing  process 
terminates;  that  is,  with  the  exception  of  the  cake-trim- 


118 


THE  MANUFACTURE  OF  LINSEED  OIL. 


ming  after  the  pressed  material  has  been  withdrawn  from 
the  press.  Great  changes  have  been  made  in  the  design 
of  this  machine  within  the  past  twenty-five  years,  but  the 
last  step  in  its  evolution  has  proved  to  be  by  far  the  most 
important  advance  yet  made.  The  change  from  the  box 
system  to  the  plate  press  is  the  particular  step  referred  to. 
Of  this  class  of  machinery  there  is  also  a  varietv  of 
makes,  each  manufacturer  claiming  distinct  and  separate 
virtues  peculiar  to  his  own  design. 

Comprehensively  speaking,  the  modern  hydraulic 
press  is  well  constructed  and  peculiarly  adapted  to  the 
nature  of  the  work  it  is  called  upon  to  perform.  The 
columns,  cylinders,  rams  and  heads  are  usually  planed 
and  turned  accurately  to  gauges,  so  that  each  part  will 
bear  its  due  proportion  of  the  strain  and  no  more,  thus 
materially  lessening  the  liability  to  breakages.  The 
rams  are  usually  sixteen  inches  in  diameter,  and  an  ag¬ 
gregate  pressure  of  about  400  tons,  or  4,000  pounds  to 
the  square  inch,  is  exerted  on  them  by  the  high-pressure 
pump,  the  latter  operating  conjointly  in  many  instances 
with  an  accumulator  as  in  the  low-pressure  system.  The 
accumulator  system  is  to  be  recommended  for  mills  op¬ 
erating  one  or  two  sets  of  presses  and  upward.  The  au¬ 
tomatic  shut-off  arrangement,  between  the  accumulator 
and  the  pump,  effectually  shutting  down  the  latter  when 
the  maximum  pressure  is  reached,  is  undoubtedly  a  great 
protection  against  breakages  and  a  most  excellent  ap¬ 
paratus  in  every  respect. 

.  A  number  of  new  features  have  been  introduced  in 
the  plate-press  system  within  recent  years.  A  16  or  18- 
cake  press,  the  former  with  hair  mats,  has  excited  con¬ 
siderable  interest  in  oil-mill  circles  of  late,  innovations 
from  the  ordinary  flat  plate  having  been  introduced. 

This  press  is  fitted  with  appliances,  resembling  minia¬ 
ture  boxes,  based  somewhat  upon  the  old  principle,  but 


THE  MANUFACTURE  OF  LINSEED  OIL. 


119 


compact  and  perfect  in  ill  respects.  It  is  fitted  with 
drainage  bars,  and  the  formation  of  the  boxes  reduces 
very  considerably  the  amount  of  fragmentary  or  oily 
edges  always  present  in  the  flat-plate  system. 

A  number  of  mills  use  presses  with  hair  mats  adjusted 
to  the  plates,  while  others  have  the  steel  corrugated 
plates  bare,  and  in  some  cases  steel  mats  or  drainage 
bars  are  used  with  the  flat  plates.  The  consensus  of 
opinion,  based  on  years  of  practical  experience  with  re¬ 
gard  to  the  relative  merits  of  the  bare  and  the  mat-plate 
systems,  is  decidedly  in  favor  of  the  former. 

The  trimming  or  paring  machine  necessary  to  trans¬ 
form  the  cake  into  presentable  shape  to  facilitate  pack¬ 
ing  and  shipment,  is  also  an  essential  feature  in  oil  mill¬ 
ing.  After  pressure  the  cakes  are  withdrawn,  pared  and 
placed  in  racks  to  cool.  Some  machines  are  constructed 
so  that  when  the  cake  to  be  pared  is  placed  on  the  iron 
slab  or  table,  a  single  stroke  of  a  side  or  end  knife,  actu¬ 
ated  by  steam  pressure,  trims  the  overlapping  edges  of 
one  side  and  end  of  the  cake,  the  same  action  of  the 
knives  performing  a  similar  function  on  the  two  remain¬ 
ing  sides  of  the  cake  when  reversed  by  the  operator. 
Some  paring  machines  are  operated  by  belts,  but  the 
cakes  taken  from  the  new  system  of  presses  previously 
alluded  to  require  but  little  paring,  and  are  merely  slid 
along  a  grooved  box  by  hand  and  against  the  edge  of  a 
knife,  the  fragments  falling  through  an  aperture  to  be 
worked  over  again. 

The  leading  American  houses  in  this  line  are  the  Stil- 
well-Bierce  &  Smith-Vaile  Company,  of  Dayton,  Ohio, 
and  the  Buckeye  Brass  and  Iron  Works  of  the  same 
town.  The  machinery  of  each  of  these  houses  can  be 
found  in  all  vegetable  oil  producing  centres  in  the  United 
States,  as  well  as  abroad,  and  it  is  safe  to  say  that  the 


120 


THE  MANUFACTURE  OF  LINSEED  OIL. 


great  reputation  which  they  have  acquired  is  well 
nicrited. 

THE  FUNCTIONS  OF  THE  ACCUMULATOR. 

The  load  on  the  plunger  is  usually  such  as  to  produce 
a  pressure  in  the  cylinder  equal  to  4,000  pounds  to  the 
square  inch  or  two  tons,  and  the  apparatus  is  made  suf¬ 
ficiently  capacious  to  contain  the  largest  quantity  of 
liquid  which  can  be  drawn  from  it  at  once  by  the  simul¬ 
taneous  action  of  all  the  hydraulic  machines  with  which 
it  is  connected. 

Whenever  the  engine  pumps  more  liquid  into  the  ac¬ 
cumulator  than  passes  into  the  cylinder  which  contains 
the  larger  plunger,  the  loaded  plunger  in  the  accumula¬ 
tor  rises  and  makes  room  in  the  cylinder  for  the  surplus ; 
but  when  on  the  other  hand  the  supply  from  the  engine 
is  less  for  the  moment  than  the  desired  quantity,  the 
plunger,  with  its  load,  descends  and  makes  up  the  defi¬ 
ciency  out  of  store. 

The  accumulator  also  serves  as  a  regulator  to  the  en¬ 
gine  or  force  pumps,  for  when  the  loaded  plunger  rises 
to  a  certain  height  it  begins  to  close  a  throttle-valve  in 
the  steam-pipe,  so  as  to  gradually  reduce  the  speed  of  the 
engine  or  pump  until  the  descent  of  the  plunger  again 
calls  for  an  increased  production  of  power. 


ROBERT  GA.NZ. 


Dr.  J.  H.  SENNER. 


THE 


Nalleiil  Frovisiomr  Mllslis  Gmv, 

ROBERT  GANZ  &  CO.,  Proprietors. 

NEW  YORK  :  CHICAGO  ; 

284-286  PEABE  STREET,  No.  11  RIAETO  BUIEDING, 

Cor.  of  Beekman.  Adjoining  Board  of  Trade. 


The  national  PROVISIONER, 

THE  ORGAN  OF  THE 

Provision  and  Meat  Industries 

OF  THE 

UNITED  STATES  AND  CANADA. 


Chicag:o,  New  York,  'Boston,  Philadelphia,  Cincinnati,  Kansas 
City,  St.  Eouis,  Eoodnn,  England. 


PUBLISHED  EVERY  SATURDAY. 


SUBSCRIPTION  PRICE: 

In  the  United  States  and  Canada,  -  -  $4.00  Per  Annum. 

In  Foreign  Countries,  -----  $6.00  Per  Annum. 

(Postage  Prepaid.) 


PUBLISHERS  OF  THE 

Pork  Packers’  Handbook  and  Directory 

OF  THE 

MEAT  AND  PROVISION  TRADES. 

440  Pages.  Price,  $10.00. 

The  Manufacture  of  Cottonseed  Oil 

AND 

ALLIED  PRODUCTS. 

95  Pages.  Price,  $3.00. 


XI 


American  Linseed  Cake  Versus  English  and  Other  Foreign 
IMakes  in  the  English  and  European  IMarkets 
(with  Analyses). 


There  are  probably  few,  if  any,  American  manufac¬ 
tured  products  or  by-products,  which,  in  proportion  to 
the  output,  are  so  largely  exported  for  consumption 
abroad  as  linseed  cake.  The  annual  output  of  linseed 
cake  in  the  United  States  may  be  estimated  at  300,000 
tons,  while  of  this  immense  quantity  probably  nine- 
tenths  are  exported,  chiefly  to  Great  Britain. 

The  quality  of  American  linseed  cake  is  of  a  diversified 
character,  and  as  a  stock-feeding  product  each  brand  is 
rated  on  the  English  market  in  accordance  with  its 
known  properties,  as  disclosed  by  the  analysis  of  the  ag¬ 
ricultural  chemist.  Sales  in  England  and  Germany  of 
American  and  other  linseed  cakes  are  effected  on  a  basis 
of  certain  oil  percentages,  the  proportion  of  the  latter 
being  usually  accepted  as  the  standard  of  commercial 
value.  Within  the  recollection  of  many  who  have  not 
yet  arrived  at  the  meridian  of  life  linseed  cake  had  but 
few  competing  factors  in  stock-feeding  centres,  while  the 
price  per  ton  has  at  times  reached  £17,  which 
is  equivalent  to  |85.  A  change  has  come  over 
the  situation;  the  number  of  stock-feeding  pro¬ 
ducts  now  in  actual  competition  with  linseed  cake 
appears  to  be  increasing,  with  unavoidable  decline  in 
values  as  a  natural  sequence.  Cottonseed  cake  is  prob¬ 
ably  the  most  powerful  and  successful  competing  feed 
product  which  the  world’s  manufacturers  of  linseed  cake 
have  encountered.  The  rapid  and  unprecedented  devel¬ 
opment  of  the  cottonseed  cake  and  meal  industry  has 
proved  decidedly  detrimental  to  the  distribution  of  lin¬ 
seed  cake.  The  differential  quotations  for  the  respective 

122 


THE  MANUFACTURE  OP  LINSEED  OIL. 


123 


products  are  immaterial,  while  but  a  few  years  ago  lin¬ 
seed  cake,  even  of  the  most  inferior  make,  readily  com¬ 
manded  a  much  higher  price.  Certain  brands  of 
American  cottonseed  cake  to-day  command  a  higher, 
price  than  many  makes  of  linseed  cake,  while  rice  meal, 
feeding  treacle,  cocoanut  meal,  palm-nut  meal,  locust 
meal  and  fenugreek  meal  each  add  their  quota,  at  lesser 
value,  in  their  restricting  influence  on  the  development 
of  linseed  cake  consumption.  In  addition  to  the  fore¬ 
going  array  of  products  competing  with  American  lin¬ 
seed  cake  abroad  we  have  also  in  the  field  Russian, 
Polish,  French,  Spanish,  Egyptian,  East  Indian,  Peru¬ 
vian,  Chilian  and  Argentine  linseed  cakes,  the  quality 
and  general  composition  of  each  being  considered  fur¬ 
ther  on. 

While  the  quantity  of  American  linseed  cake  is  very 
superior  to  that  made  twenty  years  ago,  whether  from 
the  crusher’s  or  consumer’s  standpoint,  there  is  yet  much 
to  be  done  in  many  mills  before  the  standard  of  efficient 
work  has  been  attained.  Twenty  years  ago  imported 
seed  contained  a  very  high  percentage  of  extraneous 
matter,  averaging  as  high  as  15  per  cent,  which,  un¬ 
screened,  necessarily  made  a  very  inferior  stock-feeding 
material.  To-day,  thanks  to  the  efforts  of  the  Linseed 
Association,  a  very  much  better  variety  is  imported, 
while  the  regular  domestic  product  is  all  that  can  be 
desired  in  its  freedom  from  dirt.  With  95  per  cent  of 
pure  seed  of  whatever  variety — East  India,  La  Plate  or 
Western — subjected  to  suitable  treatment,  an  excellent 
feeding  material,  friable  and  nutritive  and  containing  a 
proportion  of  oil  not  exceeding  7  per  cent  should  be  the 
invariable  result.  An  examination  of  many  of  the  brands 
of  American  linseed  cake  reveals  the  fact  that  as  high  as 
12  per  cent  of  oil  is  regularly  disposed  of  in  the  cake, 
while  in  some  instances  this  figure  is  exceeded.  On  the 


124 


THE  MANUFACTURE  OF  LINSEED  OIL. 


other  hand  certain  makes  of  linseed  cake  are  regularly 
exported  containing  an  oil  percentage  not  exceeding  7, 
while  in  one  or  two  exceptional  cases  only  from  4^  to  5^ 
per  cent  of  oil  is  left  in  the  cake.  The  primary  cause  of 
the  high  oil  percentages  referred  to  may  be  attributed  to 
defective  rolling,  while  hardness,  always  a  highly  ob¬ 
jectionable  feature  in  feeding  cake,  is  superinduced  by 
the  presence  of  an  abnormal  proportion  of  moisture. 
Not  a  few  of  the  American  brands  of  cake,  otherwise  de¬ 
sirable,  are  pronounced  inferior  by  the  English  importer 
and  consumer,  owing  to  this  cause.  Cake  of  this  char¬ 
acter  is  of  necessity  sold  at  a  material  reduction,  while 
the  American  manufacturer  by  force  of  circumstances 
must  accept  the  estimated  valuation  as  based  on  the  ana¬ 
lytical  report.  The  price  obtained  for  cake  containing 
the  heavier  proportion  of  oil,  while  a  few  shillings  per 
ton  higher  than  that  which  contains  the  normal  pro¬ 
portion,  is  far  from  being  adequate  to  compensate  for 
the  loss  of  the  surplus  and  unextracted  oil.  Aijother 
peculiar  phase  of  this  important  export  industry  and 
which  redounds  to  the  pecuniary  disadvantage  of  the 
manufacturer,  consists  in  the  anomally  that  not  infre¬ 
quently  a  cake  which  contains  a  lesser  proportion  of  oil 
commands  a  higher  commercial  value  than  that  which 
contains  a  much  heavier  oil  percentage,  primarily  owing 
to  the  latter  variety’s  possessing  a  degree  of  hardness  not 
present  in  the  former.  It  will  be  inferred  from  this  that 
the  presence  of  a  high  percentage  of  oil  in  cake  does  not 
always  imply  a  desirable  feeding  product,  or  the  softness 
of  the  material  necessarily  a  result.  In  the  cooking  pro¬ 
cess  which  the  crushed  material  is  subjected  to  prior  to 
the  pressing  operation,  surplus  moisture  will,  of  neces¬ 
sity,  produce  a  hard  cake  with  a  comparatively  light  pres¬ 
sure,  but  when  the  application  of  the  latter  is  maintained 
at  a  uniformly  high  standard — customary  in  linseed  oil 


THE  MANUFACTURE  OF  LINSEED  OIL. 


125 


mills  for  a  thorough  extraction  of  the  oil — the  material 
is  compressed  into  an  almost  impenetrable  substance  by 
that  force  which  is  essential  for  the  procurement  of  the 
oil. 

Imperfectly  crushed  seed,  cooked  with  excessive  moist¬ 
ure — two  most  reprehensible  and  destructive  processes — 
will  necessarily  produce  a  hard  cake,  together  with  a 
heavy  percentage  of  oil  as  a  result  of  normal  pressure 
application,  superinduced  by  the  foregoing  conditions. 
The  manner  in  which  improperly  rolled  seed  is  obtained, 
and  which  should  be  carefully  avoided,  is  owing  to  the 
operation  of  rolls,  which,  by  reason  of  their  protracted 
use,  cease  to  be  perfect  cylinders,  causing  the  seed  to 
pass  through  partially  crushed,  or  by  causing  a  few  to  be 
carried  to  the  rolls  beyond  their  capacity  of  grinding 
thoroughly.  A  set  of  rolls  com.prising  five,  forty-eight 
inches,  will  effectively  grind  400  bushels  of  seed  per  day, 
conditional  upon  the  latter  being  distributed  uniformly 
in  quantity  and  longitudinally  on  the  upper  roll. 

It  thus  becomes  possible  for  a  mill  well  equipped  in  all 
the  modern  appliances,  to  turn  out  a  very  inferior  grade  of 
cake,  although  made  from  a  fair  quality  of  seed,  by 
neglecting  the  condition  of  rolls,  or  defective  cooking. 
The  term  “inferior,”  which  may  be  appropriately  ap¬ 
plied  to  cake  containing  a  high  percentage  of  oil  made 
from  improperly  rolled  seed,  or  defective  cooking,  is 
transposed  when  viewed  from  the  standpoint  of  the  Eng¬ 
lish  stock  feeder.  There  are  few  things,  if  any,  which 
gladden  the  heart  of  the  average  stock  feeder  more  than 
linseed  cake  which  is  soft,  heavily  charged  with  oil,  and 
the  strata  of  which  are  turned  with  facility  by  the  blade 
of  an  ordinary  pocket-knife,  disclosing  partially  crushed 
seeds,  and  occasionally  whole  seeds  which  have  escaped 
the  rolls.  Cake  of  this  variety  is  designated  “choice” 
and  commands  a  ready  sale.  Within  a  very  recent 


126 


THE  MANUFACTURE  OF  LINSEED  OIL, 


period,  the  writer  has  analyzed  a  sample  of  American 
cake  similar  in  all  respects  to  the  foregoing,  the  oil  per¬ 
centage  being  13.10. 

Hard  cake  and  low  oil  percentages  are  looked  upon  as 
synonymous  terms,  but  it  should  be  recognized  by  the 
American  crushers,  that  it  is  possible  and  practicable 
regularly  to  turn  out  cake,  soft  and  unobjectionable  from 
any  standpoint,  and  containing  about  7  per  cent  of  oil. 
A  cake  containing  12  per  cent  of  oil  by  reason  of  exces¬ 
sive  moisture  will  be  harder  than  a  cake  containing  only 
7  per  cent  of  oil,  made  from  well-ground  seeds  and  suit¬ 
ably  cooked  and  pressed. 

To  many  the  imperfectly  understood  conditions  which 
govern  the  value  of  the  respective  grades  of  cake  in  the 
English  markets  seem  paradoxical,  but  it  is  nevertheless 
an  established  principle  that  hard  cake,  although  possess¬ 
ing  more  oil,  and,  therefore,  really  more  valuable  to  the 
consumer  (based  on  the  principle  laid  down  by  the  latter 
that  the  value  is  increased  with  the  proportion  of  oil),  sells 
for  a  lesser  figure  than  a  variety  of  cake  which  is  more 
friable,  but  contains  a  lesser  percentage  of  oil.  Agricul¬ 
tural  chemistry  has,  however,  demonstrated  that  the  de¬ 
ductions,  with  regard  to  the  value  of  cake  being  in¬ 
creased  in  the  same  ratio  as  the  percentage  of  oil  it 
contains,  are  misleading,  and  for  all  purposes  a  7  per 
cent  cake  produces  a  uniformly  superior  result. 

There  is  clearly  room  for  improvement  here,  and  it 
behooves  the  manufacturer,  in  these  times  of  sharp  com¬ 
petition  and  astonishingly  low  prices,  to  induce  radical 
changes  in  appliances,  or  methocls,  where  necessary. 

Doubtless  if  the  cake  exported  were  in  the  pulverized 
form  of  meal  the  objection  to  hardness  would  be  ob¬ 
viated,  but  the  English  agriculturalist  has  a  decided  pre¬ 
judice  against  using  the  disintegrated  product,  owing 
to  the  facility  with  which  adulteration  may  be  carried 


THE  MANUFACTURE  OF  LINSEED  OIL. 


127 


on,  and  also  to  the  liability  of  the  wind  carrying  off  the 
fine  substance  when  stock  are  feeding  in  the  open.  We 
are  thus  perforce  constrained  to  accept  the  situation  as  it 
is,  and  meet  the  requirements  of  the  case  in  the  most 
feasible  and  economical  manner,  fortified  in  the. knowl¬ 
edge  that  the  difficulty  may  be  permanently  removed 
thereby.  In  the  procurement  of  a  low  oil  percentage, 
fine  seed  grinding  becomes  absolutely  essential,  but  the 
application  of  excessive  moisture  in  the  heater  to  the 
crushed  material,  while  facilitating  the  flow  of  oil,  pro¬ 
duces  an  extremely  hard  cake,  as  previously  pointed  out. 
To  obtain  a  marketable  product,  containing  a  propor¬ 
tion  of  oil  not  exceeding  7  per  cent  friable,  and  in  all 
respects  a  faultless  stock-feeding  material,  the  following 
conditions  must  be  arbitrarily  observed;  Seed,  95  per 
cent  pure;  fine  grinding;  material  in  heater  cooked  so 
that  a  few  ounces  when  compressed  in  the  palm  of  the 
hand  will  form  into  a  compact  mass,  temperature  being 
maintained  at  160°Fahrenheit,  and  finally,  hydraulic  pres- ' 
sure  to  the  extent  of  3,800  to  4,000  pounds  pressure  per 
square  inch  or  ram  maintained  until  the  oil  drainage 
ceases.  - 

In  the  event  of  the  material  being  dry,  the  pressure 
of  the  hand  will  be  insufficient  to  form  a  paste,  and  when 
withdrawn  from  the  hydraulic  press  a  crumbling  condi¬ 
tion  will  be  apparent,  while  analysis  will  assuredly  dis¬ 
close  a  heavy  oil  percentage.  The  hand  test  for  the  de¬ 
termination  of  proportion  of  moisture  present,  may  be 
relied  upon,  but  by  reason  of  the  elevated  temperature  in 
the  material  it  must  be  performed  rapidly.  To  deter¬ 
mine  the  exact  temperature  of  the  meal,  the  writer  has 
designed  a  conveniently  constructed  thermometer, 
which,  when  inserted  into  the  mass  in  any  part  of  the 
heater,  or  withdrawing  box  beneath,  instantaneously  re¬ 
veals  the  actual  caloric  condition.  As  it  is  recognized  as 


128 


THE  MANUFACTURE  OF  LINSEED  OIL. 


one  of  the  fundamental  principles  of  oil  milling,  that  a 
certain  temperature  must  be  attained  in  the  material 
under  treatment,  failing  which,  the  oil  will  be  only 
partially  extracted,  the  necessity  for  such  a  device  is  ap¬ 
parent,  and  its  use  may  be  commended  in  the  attainment 
of  uniform  work  in  linseed  and  cottonseed  oil  mills.  Ir¬ 
regularity  in  cooking  will  affect  the  oil  yield  to  the  ex¬ 
tent  of  2  or  3  per  cent,  although  the  previous  and  suc¬ 
ceeding  consecutive  methods  may  have  been  faultless, 
while  the  sale  of  the  cake  at  current  quotations  may  be 
characterized  as  being  problematical.  Crushed  seed 
withdrawn  from  the  heater  with  insufficient  moisture, 
but  possessing  the  current  degree  of  heat,  will  result  in 
a  decreased  oil  yield,  or,  the  conditions  reversed  will  pro¬ 
duce  similar  results.  Excessive  moisture,  however,  in 
conjunction  with  the  normal  cooking  temperature,  will 
assuredly  produce  a  cake,  which  subsequent  to  storage 
for  a  few  days,  becomes  as  hard  as  stone  and  impervious 
to  ordinary  force,  the  fracture  being  accomplished  at  the 
expense  of  extreme  physical  effort.  A  few  bags  of  this 
variety  of  cake  are  sufficient  to  condemn  an  entire  con¬ 
signment  as  being  of  inferior  quality;  the  interpretation 
of  which  must  be  construed  as  pointing  to  a  very  ma¬ 
terial  reduction  from  ruling  market  quotations  for  that 
especial  brand. 

The  necessity  of  perfectly  dry  storage  for  cake,  sub¬ 
sequent  to  being  thoroughly  cooled  when  withdrawn 
from  the  press,  for  the  avoidance  of  the  mouldy  and 
sour  conditions  referred  to,  together  with  the  removal 
of  the  faulty  manufacturing  methods,  which  have  been 
shown  to  conduce  to  hardness,  is  palpable. 

Within  the  past  two  months  the  writer  has  analyzed 
twenty-two  distinct  makes  of  cake  manufactured  in  the 
United  States,  the  highest  oil  percentage  being  13.10 
and  the  lowest  4.75,  with  an  average  of  10.65. 


THE  MANUFACTURE  OF  LINSEED  OIL. 


129 


Here  are  several  copies  of  the  certificates  of  analysis 
of  as  many  brands  of  American  cake,  certified  to  by  a 
well-known  English  agricultural  chemist; 

TRADE-MARK  <A>  AMERICAN  LINSEED  CAKE. 


Oil .  9.14 

Moisture . 11.23 

^Albuminous  compounds . 33.60 

Mucilage,  sugar,  digestible  fibre,  etc.  .  .  35.23 

Phosphates,  etc.  (bone  producers) .  4.72 

Woody  fibre  (cellulose) .  6.08 


100.00 

^Containing  nitrogen,  5.36  per  cent. 

(Signed)  T,  Williams,  F.  C.  S.,  etc. 

<NP>  AMERICAN  LINSEED  CAKE. 


Oil . 12.80 

Moisture .  7.80 

^Albuminous  compounds . 33.05 

Mucilage,  sugar,  digestible  fibre,  etc.  .  .  .  36.93 

Phosphate,  etc.  (bone  producers) .  4.77 

Woody  fibre . 7.10 


100.00 

*  Containing  nitrogen,  5.27  per  cent, 

(Signed)  T.  Williams,  F.  C.  S.,  etc. 

N.  W.  L.  O.  CO.  AMERICAN  LINSEED  CAKE. 


Oil .  8.83 

Moisture . 10.06 

^Albuminous  compounds . 33.50 

Mucilage,  sugar,  digestible  fibre,  etc.  . .  .  35.59 

Phosphate,  etc.  (bone  producers) .  4.92 

Woody  fibre  (cellulose) .  7-10 


100.00 

*Containing  nitrogen,  5.34  per  cent. 

(Signed)  T.  Williams,  F.  C.  S.,  etc. 


130 


THE  MANUFACTURE  OF  LINSEED  OIL. 


<M>  AMERICAN  LINSEED  CAKE. 

Oil. . 

Moisture . ^ 

*  Albuminous  compounds . 

Mucilage,  sugar,  digestible  fibre,  etc ... 
Phosphates,  etc.  (bone  producers)  .  .  .  . 
Woody  fibre  (cellulose) . 


8.59 

9.70 

33.46 

36.00 

5.06 

7.18 


100.00 

*  Containing  nitrogen,  5.33  per  cent. 

The  foregoing  data  will  be  sufficient  to  convey  a  fairly 
accurate  knowledge  concerning  the  general  character 
of  linseed  oil  milling  as  it  exists  in  the  United  States 
to-day;  and,  while  there  is  urgent  need  of  mechanical 
and  methodical  reformation  in  too  manv  instances,  it 
must  be  conceded  that  we  are  still  in  advance  of  the  work 
of  other  nationalities,  as  demonstrated  by  the  following 
analyses.  The  following  certificate  of  analysis  repre¬ 
sents  a  sample  of  English-made  cake  of  95  per  cent  pure 
seed: 

AD  (branded  on  surface  OF  CAKE). 

Oil . 12.88 

Moisture . 13.52 

Albuminous  compounds  (flesh  formers) .  30.57 

Mucilage,  sugar,  digestible  fibre,  etc.  .  .  31.88 

Woody  fibre . 6.03 

Ash .  5^ 

100.00 

Nitrogen,  4.83;  equal  to  ammonia,  5.86  per  cent. 

(Signed)  .  M.  D.  Penney,  F.  C.  S, 

Hull,  April  21,  1895. 

A  sample  of  “A  D,”  analyzed  by  the  writer  recently, 
exceeded  14  per  cent  of  oil,  while  the  stipulation  covering 
sales  of  this  brand  calls  for  an  oil  percentage  between 
12  and  14.  A  sample  of  'S'  linseed  cake  of  English 
make  revealed  13.05  per  cent  of  oil.  While  the  percent¬ 
ages  of  oil  are  heavy  in  these  instances,  the  gravity  of  the 


THE  MANUFACTURE  OF  LINSEED  OIL. 


131 


case  is  not  of  such  moment  as  in  the  case  of  American 
makes,  for  the  well-known  reason  that  oil  and  cake  values 
in  Great  Britain  are  viewed  from  a  standpoint  at  decided 
variance  from  that  which  we  attach  to  the  products  here. 
Oil  being  valued  at  a  higher  commercial  standard  here, 
its  thorough  extraction  becomes  a  matter  of  material 
consequence,  while  lesser  importance  is  attached  to  the 
question  in  English  and  other  foreign  manufactories, 
the  cake  being  the  primary  product,  and  the  oil  the 
by-product. 

A  brand  of  Russian  linseed  cake,  H.  O.  C.,  now  offered 
on  the  English  market,  contains  the  extraordinary  per¬ 
centage  of  16.28  of  oil  guaranteed,  while  the  “Harbur- 
ger”  brand  (Russian),  like  the  former  is  sold  on  a  basis 
of  12  per  cent  of  oil. 

German  cake  of  Bremen  make  is  offered  to-day  on 
the  English  market  with  a  guaranteed  percentage  of  10 
to  14  of  oil;  also,  round  Polish  cakes  at  14  to  15  per 
cent  of  oil,  and  square  French  cakes  (Marseilles)  at  12 
per  cent  of  oil.  East  Indian  and  Egyptian  lin¬ 
seed  cakes  are  guaranteed  to  contain  from  12 
to  14  per  cent  of  oil,  and  Chilian,  Peruvian  and 
Argentine  cake  from  12  to  15  per  cent  of  oil. 
The  following  copy  of  certificate  of  analysis  will  further 
confirm  the  analytical  work  of  the  writer,  who  has  tested 
each  of  the  foregoing  varieties  of  cake: 

TRADE-MARK  “s.”  CHILIAN  LINSEED  CAKE. 


Oil . 13.18 

Moisture .  9-07 

*Albuminous  compounds . 28.90 

Mucilage,  sugar,  digestible  fibre,  etc.  .  .  30.39 

Woody  fibre . 12.66 

Mineral  ash .  5.80 


100.00 

*Containing  nitrogen,  4,62  per  cent. 

(Signed)  ^  T.  Williams,  F.  C.  S.,  etc. 


132 


THE  MANUFACTURE  OF  LINSEED  OIL. 


There  are  several  small  mills  in  operation  in 
England  which  are  rarely  without  a  supply  of  lin¬ 
seed  cake  of  American,  Russian,  or  other  makes, 
and  which  are  known  to  contain  a  high  oil  per¬ 
centage.  These  cakes  are  reduced  to  meal  and 
gradually  worked  off  in  various  proportions,  with 
the  regular  charge  of  crushed  seed  in  the  cooking 
kettles,  and  from  them  6  to  8  per  cent  of  oil  is  obtained, 
the  cake  being  ultimately  disposed  of  at  a  price  actually 
higher  than  that  paid  for  the  reworked  material.  It  is 
by  these  means  that  the  enterprising  English  oil  mil¬ 
ler  turns  many  an  honest  penny  at  the  expense  of  the 
American  and  other  manufacturers.  The  moral  is  ob¬ 
vious. 

COMPOUND  cake:  a  new  outlet  for  mill-feeding 

PRODUCTS. 

The  bulletin  recently  issued  by  the  Secretary  of  Agri¬ 
culture  concerning  the  practicability  of  increasing  the 
consumption  of  American  stock  feeding  products, 
whether  of  the  artificial  or  unmanufactured  varieties,  alike 
in  domestic  and  foreign  consumption,  is  fraught  with  in¬ 
terest  to  the  seed  crushing  industry.  The  introduction 
of  a  system  in  oil  mills  by  means  of  which  a  feeding  cake 
could  be  compounded  of  various  constituents,  the  rela¬ 
tive  quantities  of  each  being  proportioned  to  meet  cer¬ 
tain  arbitrary  requirements  in  stock  feeding,  which  is 
lacking  in  pure  mill-feeding  products,  such  as 
oil  cake,  should  prove  a  welcome  and  profitable 
innovation  or  adjunct  to  the  ordinary  seed 
crushing  business  of  the  country.  While  the  in¬ 
troduction  of  a  system  such  as  referred  to  would 
partake  of  a  novel  character  in  the  list  of  American 
manufactured  products,  the  principle  is  not  new,  how¬ 
ever.  In  English  oil  milling  centres  the  manufacture  of 


THE  MANUFACTURE  OF  LINSEED  OIL. 


133 


a  mixed,  or  compounded  cake,  of  which  cot¬ 
ton  cake  meal  forms  an  important  constituent, 
is  carried  on  to-day  on  a  most  extensive  scale. 
It  is  this  circumstance,  more  than  all  else,  which 
has  contributed  to  the  decline  in  price  of  mill 
feeding  products  of  the  unmixed  or  pure  variety,  such  as 
standard  brands  of  cotton  and  linseed  cakes.  During 
the  past  twenty  years  the  latter  material  has  declined  in 
value  at  a  rate  exceeding  100  per  cent,  while  at  times 
sales  are  difficult  with  regard  to  either  feeding  product, 
even  at  such  abnormally  low  prices  which  have  marked 
the  course  of  the  current  season.  While  in  the  aggre¬ 
gate  the  consumption  of  mill-feeding  products  has 
gradually  increased,  preference  is  given  in  numerous  in¬ 
stances  in  Great  Britain  to  the  compounded  feeding 
cake,  of  which  American  decorticated  cake  meal  forms 
a  component  part.  Mill-feeding  stuffs — linseed,  rapeseed 
and  cottonseed  cakes — are  largely  exported  to  Germany 
and  England  from  Russia,  Poland,  Spain  and  Egypt, 
while  Peru,  Chili  and  Argentine  add  their  respective 
quota  to  the  whole.  Although  American  feeding  stuffs 
are  of  a  superior  quality,  cotton  cake  especially  being  in¬ 
comparable,  low-priced  feeding  stuffs  manufactured  in 
the  countries  mentioned  affect  the  demand  for  same  to  a 
greater  or  less  extent.  It  is  a  significant  fact  that  the 
compound  cake  which  stands  highest  in  favor  abroad 
is  that  which  contains  a  substantial  proportion  of  Amer¬ 
ican  decorticated  cake  meal.  The  progressive  American 
manufacturers  should  bear  this  important  fact  well  in 
mind,  the  necessity  of  devising  adequate  means  to  im¬ 
prove  the  occasion  being  palpable. 

It  is  recognized  among  agriculturalists  who  resort  to 
artificially-prepared  stock-feeding  materials  that  in  near¬ 
ly  all  instances  American  cotton  cake  is  too  concentrated 
for  feeding  alone,  its  consumption  being  usually  accom- 


134 


THE  MANUFACTURE  OF  LINSEED  OIL. 


plished  in  association  with  certain  proportions  of  farin¬ 
aceous  substances.  This  circumstance  resolves  into  a 
powerful  argument  in  favor  of  the  compound  cake.  It 
must  not  be  forgotten,  however,  that  owing  to  the  risks 
involved  in  feeding  to  live  stock  unknown  or  @heap 
brands  of  feeding  cake,  not  a  few  of  the  prominent 
British  agriculturalists  are  in  favor  of  purchasing  the 
pure  cake  and  adding  the  dilutent  themselves.  As  the 
cheap  adulterated  stuffs — of  which  there  is  always  a 
supply  abroad — are  being  more  readily  recognized  than 
heretofore,  they  are  carefully  avoided  by  the  leading  cake 
consumers;  while,  on  the  other  hand,  certain  brands  of 
mixed  cake  of  known  properties  are  also  becoming  more 
widely  known,  and  are  in  correspondingly  increased  de¬ 
mand.  Were  an  American  compound  cake  placed  on 
the  foreign  markets  possessing  the  essential  qualifica¬ 
tions,  the  possibility  of  trade  expansion,  with  especial 
reference  to  cotton  cake,  would  be  practically  unlimited, 
while  that  of  other  feeding  substances  would  also  be 
very  appreciably  increased. 

Nearly  twenty-four  years  ago  the  late  Dr.  Augustus 
Voelker,  of  the  British  Agricultural  Society,  recognizing 
the  need  of  a  combination  of  feeding  materials  in  con¬ 
venient  form,  possessing  to  the  fullest  extent  practicable 
the  essential  nutritive  attributes,  while  modifying  the  ex¬ 
cessive  nitrogenous  properties  characteristic  of  mill 
products,  formulated  the  idea  now  suggested  to  the 
American  trade,  the  merit  of  cheapness  being  an  addi¬ 
tionally  attractive  feature.  Experiments  on  a  small  scale 
were  made  of  various  combinations — the  primacy  of 
American  decorticated  cotton  cake  among  the  mill  or 
unmanufactured  feeding  stuffs  being  an  invariable  guar¬ 
antee  of  its  presence  therein — results  proving  uniformly 
successful.  In  some  instances,  Indian  corn  and  cotton 
cake  in  disproportionate  quantities  were  jointly  com- 


THE  MANUFACTURE  OF  LINSEED  OIL. 


135 


pressed,  while  linseed  cake,  cocoanut,  palmnut,  rice,  rape 
cake,  all  in  ground  form,  were  variously  added,  while 
also  wheat  bran,  oats  and  feeding  treacle  were  tried  simi¬ 
larly.  The  nitrogenous  element  in  certain  materials 
being  thoroughly  incorporated  with  other  nutritive  in¬ 
gredients  of  a  less  concentrated  character,  a  “balanced 
ration”  was  the  resultant  product.  Within  the  past  ten 
years  in  England  the  manufacture  of  compound  cake  of 
the  character  described  has  assumed  enormous  propor¬ 
tions.  The  first  to  appropriate  Dr.  Voelker’s  recipes  on 
a  manufacturing  scale  was  the  Waterloo  Mills  Cake  & 
Warehousing  Co.,  Limited,  Hull.  The  present  output 
of  this  concern,  which  is  not  equal  to  its  capacity,  consists 
of  350  tons  of  compound  cake,  150  tons  of  undecorticated 
cotton  cake  and  120  tons  of  linseed  cake  weekly,  figures 
which  adequately  represent  the  relative  appreciation  of 
the  consumers  for  the  respective  products.  In  Liverpool 
the  Bibby  compound  feeding  cake  is  manufactured  to  the 
extent  of  800  tons  per  week,  while  at  this  writing  so 
great  is  the  constantly  increasing  demand,  that'^e  Bibby 
mill  capacity  is  being  increased  300  tons  per  week.  Im¬ 
mense  quantities  of  cotton  meal  are  annually  used  in  this 
mill,  which  is  operated  exclusively  on  this  form  of  feed¬ 
ing  cake.  The  demand  for  compound  cake  is  of  such  a 
character  that  the  manufacturers  are  taxed  to  execute 
their  orders.  The  business  in  this  form  of  cake,  notwith¬ 
standing  the  dimensions  it  has  already  assumed,  is  only 
in  its  incipiency,  and  as  the  number  of  manufacturers  are 
comparatively  few,  the  fringe  of  the  market  has  been 
touched  only.  Without  reference  to  the  practically 
illimitable  agricultural  districts  within  the  confines  of  the 
United  States  where  the  introduction  of  such  a  valuable 
commodity  would  prove  a  veritable  boon,  there  are  yet 
vast  sections  in  Europe  and  Great  Britain  where  this 
class  of  cake  has  yet  to  be  introduced.  English  seed 


136 


THE  MANUFACTURE  OF  LINSEED  OIL. 


crushers,  to  protect  their  languishing  cake  trade,  are  real¬ 
izing  the  necessity  of  adding  to  their  regular  mill  work 
the  manufacture  of  a  compound  cake.  A  number  have 
already  done  so,  while  many  more  are  contemplating  a 
similar  step.  There  are  a  number  of  well-known  brands 
of  com.pound  cake  on  the  English  markets  which  are 
preferred  before  other  forms  of  cakes  by  the  stock 
feeders,  the  slightly  reduced  price  being  but  a  second¬ 
ary  consideration.  Here  are  the  names  of  several  popu¬ 
lar  brands:  “H.  &  C,”  “One  and  All,”  “Mayon,”  “Dairy 
No.  1,’*  “Waterloo,”  “Grindall,”  “Eagle  Champion,”  etc. 

Several  years  ago  the  writer  suggested  the  practicabil¬ 
ity  and  ultimately  the  necessity  of  this  movement  as  an 
increased  outlet  for  American  mill  products,  while  ex¬ 
tending  trade  in  corn,  etc.  The  demand  for  compound 
cake  in  England  has  diminished  the  consumption  of  our 
feeding  stuffs  very  materially;  nor  may  we  expect  a  per¬ 
manent  betterment  of  existing  conditions  until  the  reme¬ 
dial  measures  within  our  reach  are  energetically  pur¬ 
sued.  American  compound  cake,  placed  on  the  English 
and  Continental  markets,  would  unquestionably  receive  a 
similar  recognition  as  that  formerly  accorded  the  concen¬ 
trated  foods  or  mill  products,  which  at  all  times  success¬ 
fully  compete  with  the  makes  of  other  countries.  As 
in  the  case  of  the  pure  cakes,  it  can  be  laid  down  at  any 
prominent  distributing  point  abroad  at  a  lower  rate  than 
is  possible  to  manufacture  same  outside  the  United 
States,  the  supply  of  ingredients  of  all  classifications  be¬ 
ing  cheap  and  plenteous. 

As  no  feasible  argument  may  be  advanced  showing 
why  a  compounded  American  cake  would  not  have  an 
excellent  prospect  of  success  in  being  disposed  of  abroad 
in  competition  with  English-made  compounds,  every¬ 
thing  bearing  on  the  situation  unmistakably  indicating 
the  contrary  result,  it  behooves  the  American  seed 


THE  MANUFACTURE  OF  LINSEED  OIL. 


137 


crusher  to  adopt  measures  with  the  object  of  expedit¬ 
ing  such  a  movement.  The  languishing  stock-feeding 
trade  of  the  country  urgently  needs  a  stimulating  resto¬ 
rative  to  secure  the  former  position  it  held  in  foreign 
markets.  To  attain  this,  suitable  machinery  must  be 
procured.  This  latter  is  free  from  complexity,  the  manu¬ 
facturing  operation  being  of  a  much  more  simple  charac¬ 
ter  than  that  which  is  involved  in  the  manufacture  of  the 
pure  cake,  the  necessity  of  oil  extraction  being  pre¬ 
cluded.  The  apparatus  or  plant  necessary  is  of  a  com¬ 
paratively  inexpensive  character.  A  set  of  presses  com¬ 
prises  two,  upon  which  a  heater  rests,  the  cake  being 
usually  circular.  The  heater  (jacketed)  increases  the 
temperature  of  the  material,  as  its  name  implies,  and  in 
which  it  also  receives  a  certain  amount  of  moisture,  so 
that  when  pressure  is  applied  a  compact  substance,  or 
cake,  is  formed  with  facility.  The  pressure  needed  is 
comparatively  light,  and  the  duration  of  same  to  produce 
a  batch  of  suitably  pressed  material  is  brief.  This  will  be 
readily  understood  when  it  is  stated  that  with  a  set  of 
cornpoimd-cake  presses  from  500  to  800  cakes  per  hour 
are  turned  out  when  regular  work  is  being  maintained. 
Oblong,  square,  tapering  cakes  are  also  distinguishing 
features  of  some  brands,  the  form  of  press  being  accord¬ 
ingly  designed.  The  material  descends  through  openings 
in  the  press  heads  in  quantities  sufficient  to  form  a  single 
cake,  the  operation  being  simple,  and,  as  already  implied, 
being  susceptible  of  being  continuously  repeated  in  rapid 
succession. 

When  sufficient  time  has  elapsed  for  the  cake  to  cool, 
its  storage  or  transportation,  even  on  prolonged  sea 
voyages,  may  be  effected  with  less  risk  of  decomposition 
or  moldiness  than  that  which  is  inseparable  from  the 
shipment  of  pure  feeding  cakes.  According  to  the  mate¬ 
rials  employed  in  compounding  cake,  the  grinding  and 


138 


THE  MANUFACTURE  OF  LINSEED  OIL. 


reducing  machinery  varies,  the  necessary  screens  and 
mixers  in  like  manner.  The  dimensions  of  the  various 
brands  of  compound  cake  are  about  as  follows:  Sixteen 
inch(  s  diameter;  26  x  11  inches;  21^  x  12^  inches; 
26^  X  12^  inches;  23^  x  13  inches,  etc. 

CAMEL-HAIR  PRESS  CLOTH. 

Concerning  the  use  of  press  cloth  in  oil  milling,  there 
is  much  to  be  said.  However  perfect  the  material  may 
be,  with  improper  pressing  or  cooking  the  fabric  will 
undoubtedly  be  destroyed  long  before  its  usefulness 
should  have  expired  under  normal  conditions. 

As  is  well  known  there  are  various  makes  of  press 
cloth  on  the  market.  It  is  a  notorious  fact  that  at 
times  a  new  press  bag  will  be  destroyed  on  the  first  day 
of  service.  This  is  invariably  due  to  defective  material 
or  improperly  made  goods. 

The  writer  has  used  the  Perkins  press  cloth  for  twelve 
years,  and  can  testify  to  its  uniformly  good  quality  and 
general  satisfaction  under  normal  treatment,  excepting 
in  the  case  of  an  irresponsible  or  biased  judgment  which 
has  happened  on  one  occasion,  to  the  writer’s  knowledge; 
otherwise  we  have  never  heard  of  a  complaint. 

The  firm  of  J.  T.  Perkins  Company  conscientiously 
and  consistently  offer  a  reliable  press  cloth,  and  it  is  the 
company’s  boast  that  under  no  conditions  will  anything 
in  the  way  of  crude  material  be  allowed  within  their  fac¬ 
tory  precincts  which  is  not  of  the  very  best  quality. 

Concerning  the  Sugden  press  cloth,  which  is  manu¬ 
factured  at  West  Chelmsford,  Mass.,  we  have  this  to 
say:  It  is  singularly  well  adapted  for  the  use  of  linseed 
and  cottonseed  oil  mills. 

The  writer  has  given  their  material  a  severe  test,  and  it 
has  stood  same  in  a  very  satisfactory  manner.  It  will  be 
interesting  for  the  oil  mill  fraternity  to  know  that  a 


THE  MANUFACTURE  OF  LINSEED  OIL. 


139 


good  camel-hair  press  cloth,  well  made  from  sound  mate¬ 
rial,  same  being  sufficiently  long  'staple,  should  last, 
with  fair  treatment,  six  weeks,  the  mill  running  twenty- 
three  hours  out  of  the  twenty-four,  and  the  system  and 
pressroom  being  six  pages  per  hour. 

The  writer  takes  pleasure  in  recommending  the  two 
firms  mentioned  as  being,  as  far  as  his  knowledge  goes, 
the  only  reliable  camel-hair  press  cloth  manufacturers 
in  the  United  States. 

OIL  boiler’s  driers. 

Oil  boiling  by  the  steam  process  has  rapidly  grown  in 
favor  within  recent  years.  The  old  system  of  boiling  by 
fire  is  rapidly  dying  out,  and  is  inadequate  to  meet  mod¬ 
ern  demands.  The  advantages  of  the  steam  process, 
when  compared  with  the  older  system  referred  to,  are 
generally  admitted  by  those  who  have  tried  both  sys¬ 
tems,  and  we  would  strongly  recommend  manufacturers 
who,  at  considerable  inconvenience,  boil  by  the  old  style, 
to  give  proper  consideration  to  the  subject  upon  which 
we  propose  to  dwell.  The  advantages  deriving  from  the 
new  system  may  be  ascribed  to  various  causes.  In  the 
first  place,  no  apprehensions  may  be  entertained  of  con¬ 
flagration  caused  by  the  oil  swelling  while  under 
treatment.  A  uniformity  of  temperature  may  be 
obtained  thioughout  the  process  with  ordinary 
attention;  and,  lastly,  science  has  made  the  opera¬ 
tion  practicable  and  profitable  by  the  blending 
and  solution  of  various  siccative  compounds  pre¬ 
pared  in  linseed  oil  in  consistent  proportions, 
and  which  are  included  under  the  designation  of  liquid 
drier.  In  these  days  of  sharp  competition  it  devolves 
upon  the  seed  crusher  to  give  consideration  to  this  im¬ 
portant  branch  of  his  business,  and  select  the  most  eco¬ 
nomical  method  of  bringing  about  a  satisfactory  result; 


140 


THE  MANUFACTURE  OF  LINSEED  OIL. 


that  is,  a  good  drying  oil  for  all  practical  purposes  at  a 
minimum  of  cost. 

The  liquid  drier  is  especially  adapted  for  use  in  the 
steam-boiled  process.  The  covered  and  jacketed  pot 
or  kettle  in  which  the  oil  is  treated  confines  the  objec¬ 
tionable  odors,  always  present  in  oil  boiling,  in  a  much 
more  perfect  manner  than  is  possible  in  the  fire  system 
of  boiling.  The  intensity  of  the  heat,  which  is  a  prom¬ 
inent  feature  of  the  latter  process,  has  doubtless  much 
to  do  with  this  result,  as  whatever  means  have  been  de¬ 
vised  to  restrain  or  destroy  these  injurious  odors,  none 
has  been  found  effective. 

Where  an  oil  is  boiled  by  steam  heat  the  pungent  odors 
are  more  readily  conveyed  through  conveniently  ar¬ 
ranged  vapor  pipes  to  the  furnace  chimney  and  dis¬ 
charged  high  in  the  air,  out  of  reach  of  human  eyes  and 
lungs.  The  same  appliances  for  the  removal  of  the  ob¬ 
noxious  substances  may  be  in  operation  with  the  fire- 
boiled  system,  but,  as  stated,  without  success.  Despite 
all  precautions,  the  deadly  fumes  and  vapors  will  slowly 
curl  from  each  chink,  or  smallest  aperture  visible,  either 
in  or  around  the  iron  hood  which  usually  covers  the 
boiling  caldron,  much  to  the  discomfort  of  the  attend¬ 
ant.  Where  the  latter’s  duty  calls  for  frequent  removal 
of  the  small  movable  side  covering  to  watch  the  process 
of  the  operaton,  or  to  agitate  the  mass  by  hand  in  the 

% 

absence  of  mechanical  power,  matters  are  much  worse. 
The  comparative  absence  of  these  conditions,  where  the 
liquid  drier  of  genuine  quality  is  used,  whether  by  the 
fire-boiled  or  steam-heating  process,  is  a  powerful  argu¬ 
ment  in  favor  of  that  form  of  drier  as  compared  with  the 
solid  variety.  That  this  impression  is  gradually  gaining 
ground  among  oil  boilers  is  unquestioned,  and  the  logic 
which  superinduces  the  change  is  unassailable. 

Where  a  good  liquid  drier  is  used  in  oil,  heated  in  the 


THE  MANUFACTURE  OF  LINSEED  OIL. 


141 


Steam-jacketed  kettle  to  a  temperature  varying  between 
230°  to  280°  F.,  in  conjunction. with  a  blast  of  air  forced 
into  the  oil,  a  good  body  is  given  to  the  latter,  a  satisfac¬ 
tory  color  is  obtained  (although  on  this  latter  point  it  is 
impossible  to  suit  the  views  of  all),  while  for  all  practical 
purposes  its  main  features  bear  favorable  comparison 
with  the  older  system,  possessing  fully  what  must  be  ad¬ 
mitted  to  be  the  most  essential  characteristic  property  of 
a  boiled  oil,  viz.,  the  property  of  drying  quickly. 

A  siccative  material  is  any  compound  which,  added  to 
linseed  oil,  either  hot  or  cold,  hastens  its  drying  qualities, 
which  are  naturally  slow,  and  renders  its  use  in  painting 
and  varnishing  practicable  and  efficient.  Liquid  drier 
is  simply  a  concentrated  boiled  oil.  The  most  reliable 
form  of  drier  is  a  compound  of  bases  having  the  property 
of  several  oxides  and  series  of  salts. 

Formerly  oil  was  boiled  by  simply  adding  red  lead, 
and  even  at  the  present  advanced  stage  of  the  business 
not  a  few  crushers  in  the  Central  and  Western  States 
adhere  to  this  primitive  method.  While  red  lead  unques¬ 
tionably  possesses  a  considerable  proportion  of  oxygen, 
and  therefore  gives  to  the  oil  with  which  it  is  treated  su¬ 
perior  drying  qualities  when  added  at  a  high  tempera¬ 
ture,  its  use  in  the  majority  of  instances  is  reprehensible. 

The  necessity  of  an  effective  drier  in  oil  boiling  is  of 
the  greatest  importance,  and  too  much  attention  cannot 
be  bestowed  on  the  selection  of  same.  There  are  liquid 
driers  on  the  market  to-day  which  are  undeserving  of  the 
name.  On  the  other  hand,  there  are  driers  made  in 
similar  form,  which  are  admirably  adapted  for  the  steam- 
boded  process  and  unexceptional  in  their  results.  The 
practicability  of  making  a  good  drier  of  oil  by  means 
of  this  form  of  drier  at  a  medium  temperature,  say,  260° 
to  280°,  renders  the  use  of  the  steam-boiled,  or  new 
process  oil,  especially  advantageous.  The  writer  has 


142 


THE  MANUFACTURE  OF  LINSEED  OIL. 


witnessed  the  use  of  the  Pratt  &  Lambert  drier  for  ten 
years  with  uniform  satisfaction.  Very  excellent  boiled 
may  be  regularly  made  with  this  form  of  drier  in  the  pro¬ 
portion  of  10  per  cent  of  drier  to  the  weight  of  oil.  This  is 
a  well-known  and  reliable  house,  and,  therefore,  will 
place  on  the  market  nothing  but  that  which  is  absolutely 
genuine,  and  the  author  takes  pleasure  in  commending 
them  to  the  attention  of  the  seed-crushing  trade  of  the 
United  States. 

The  necessity  of  efficient  driers  in  oil  boiling  is,  there¬ 
fore,  apparent,  and  too  much  attention  cannot  be  be¬ 
stowed  on  the  selection  of  a  drier  which  is  not  misnamed. 
There  are  liquid  driers  on  the  market  to-day  which  are 
undeserving  of  the  name;  on  the  other  hand,  there  are 
driers  made  in  similar  form,  admirably  adapted  for  either 
the  fire  or  steam-boiled  process,  and  unexceptionable  in 
their  results.  The  practicability  of  making  a  good  dry¬ 
ing  oil  by  means  of  this  form  of  drier  at  a  medium  tem¬ 
perature,  renders  the  use  of  steam-boiled  or  new-process 
oil  especially  advantageous,  although  equally  good  re¬ 
sults  may  be  obtained  by  the  use  of  the  same  form  of 
drier  in  the  older  process,  with  this  difference  in  its  favor 
that  a  moderate  temperature  is  sufficient.  Anhydrous 
binoxide  of  manganese,  which  contains  a  large  propor¬ 
tion  oxygen,  is  a  valuable  ingredient  in  a  well-prepared* 
drier. 

The  transition  of  oil  on  a  level  plane  from  a  fluid  condi¬ 
tion  to  that  of  a  dry  and  glossy  surface  is  hastened  by  the 
absorption  of  oxygen  due  to  the  inherent  properties  of 
the  presence  of  acetate  of  lead,  minium,  manganese,  or 
other  compounds.  The  use  of  litharge  in  oil  boiling  has 
long  been  known,  but  the  few  who  are  familiar  with  its 
use  zealously  guarded  the  knowledge.  The  super-addi¬ 
tion  of  red  lead  or  of  binoxide  of  manganese  is  of  more 
recent  date. 


THE  MANUFACTURE  OF  LINSEED  OIL. 


143 


Some  of  the  ingredients  of  a  good  drier,  that  is,  those 
which  are  not  oxides,  are  capable  of  discharging  their 
peculiar  functions  at  moderate  temperature.  Their 
especial  utility  consists  in  their  direct  action  on  the 
mucilaginous  and  vegetable  matter  present  in  the  oil, 
thus  materially  aiding  the  latter  in  its  absorption  of  the 
oxygen  from  the  metallic  oxides.  But  this  property  of 
the  non-oxidizing  ingredients,  with  regard  to  tempera¬ 
ture,  is  of  little  avail,  because,  as  previously  pointed  out, 
a  high  temperature  is  essential  in  the  preparation  of  a 
drier  to  render  the  oxides  efficient.  The  complete  nulli¬ 
fication  of  the  action  of  vegetable  or  mucilaginous  mat¬ 
ter,  which  is  a  well-known  preventative  of  the  drying  of 
an  oil,  is  one  of  great  significance.  Sulphate  of  zinc 
ranks  among  the  most  important  of  all  substances  for 
this  office. 

When  a  manganese  compound  is  used,  a  high  tem¬ 
perature  is  not  essential  when  oil  boiling  is  progressing. 
It  should  not  be  forgotten  that  the  correct  temperature 
necessary  to  render  a  liquid  drier  potent  has  been  main¬ 
tained  during  the  process  of  its  manufacture,  so  that  its 
full  powers  are  capable  of  development  when  added  to  the 
oil  at  a  temperature  varying  between  175°  and  260° 
Fahrenheit,  but  when  an  intense  heat  is  maintained 
(which  is  indispensable  when  a  solid  drier  is  used),  con¬ 
siderable  precautions  are  necessary  to  guard  against  the 
danger  of  swelling  and  conflagration.  Unremitting  at¬ 
tention  must  be  given  in  the  latter  system  and  grave 
risks  are  incurred,  all  precautions  and  devices  to  that 
end  notwithstanding.  No  possible  precaution  can  guard 
against  the  possibility  of  a  crack  or  flaw  in  the  casting 
widening  when  a  batch  of  oil  is  under  treatment.  At  any 
moment  during  the  period  when  the  heat  is  at  its  maxi¬ 
mum  point,  a  crack  may  develop,  when  deplorable  con¬ 
sequences  are  inevitable.  In  this  system  such  risks  can- 


144 


THE  MANUFACTURE  OF  LINSEED  OIL. 


not  be  obviated,  as  an  intense  heat  is  required  for  proper 
fusion  of  the  solid  drier  with  the  oil. 

The  liability  of  the  caldron  casting  to  cracking  sug¬ 
gested  the  feasibility  of  increasing  the  thickness  of  the 
metal  at  the  bottom,  where  the  heat  is  most  intense;  but 
castings,  however  carefully  molded,  are  not  to  be  at  all 
times  depended  upon,  and  this  is  especially  so  with  re¬ 
gard  to  their  use  in  oil  boiling. 

The  oxygen  in  the  liquid  drier,  always  assuming  it  to 
be  the  genuine  article,  is  freely  given  out  to  the  oil  at 
the  temperature  named.  To  procure  the  desired  dark- 
brown  shade,  which  the  views  of  the  consumer  sometime 
demand,  a  lead  salt  is  added  in  variable  quantities — the 
correct  proportion  the  practical  drier-maker  can  readily 
solve  to  suit  the  respective  needs  of  each  case. 

The  Atlantic  Drier  Co.,  Drexel  Building,  Philadel¬ 
phia,  manufacture  a  drier  for  the  especial  use  of  oil 
boilers,  which  has  also  become  very  much  in  demand 
for  the  seed  crusher’s  purposes.  Writer  has  given  this 
brand  of  drier  numerous  tests  under  all  conditions,  and, 
from  the  point  of  economy  for  the  procurement  of  de¬ 
sirable  results,  its  use  on  a  manufacturing  scale  is  all 
that  can  be  desired.  This  drier  will  mix  perfectly 
with  linseed  oil,  turpentine  or  benzene  without  curdling 
or  separating.  It  is  a  very  strong,  heavy-bodied  drier; 
its  chief  mission  is  making  boiled  linseed  oil.  Contain¬ 
ing,  as  it  does,  the  most  approved  boiling  and  drying 
agents  in  greatly  concentrated  form  and  entirely  free 
from  volatile  matter,  it  does  not  thin  the  body  of  lin¬ 
seed  and  it  is  only  necessary  to  mix  a  small  amount 
with  raw  linseed  to  obtain  an  oil  having  all  the  char¬ 
acteristics,  properties  and  power  of  the  best  boiled  oil. 
Such  a  mixture  may  be  made  in  tanks  or  barrels  and  at 
the  most  convenient  temperature  from  200°  Fahrenheit 


THE  MANUFACTHRE  OF  LINSEED  OIL. 


145 


down  to  80°  Fahrenheit.  Heat  is  unnecessary  if  the  raw 
linseed  is  well  settled  and  free  from  moisture. 

Ten  per  cent  or  five  gallons  of  this  drier  to  the  barrel 
of  raw  linseed  oil,  makes  a  full  strength  boiled  oil,  and 
a  moment’s  calculation  on  their  prices  will  prove  this 
done  without  any  advance  in  cost. 

This  firm  manufactures  another  form  of  drier,  differ¬ 
ing  from  other  oil  driers,  as  it  sets  quickly  alone ;  it  gives 
a  fine  gloss  and  hard  finish,  almost  replacing  varnish. 
Like  the  latter  variety,  it  may  be  used  for  boiling  linseed 
oil,  and  will  give  a  stronger  drying  oil  used  in  the  same 
proportions;  it  has,  however,  another  and  equally  valu¬ 
able  field:  because  of  its  great  concentration  and 
strength,  it  may  be  thinned  or  reduced  with  turpentine 
or  benzene  and  a  japan  or  liquid  drier  produced,  ranging 
in  cost  from  forty-five  cents  down  to  twenty  cents,  equal 
in  drying  power  to  the  usual  fifty-cent  and  seventy-five 
cent  driers.  Should  very  quick  drying  be  desired, 
Indiglos — a  special  form  of  drier  thus  designated  and 
made  by  the  A.  D.  Co. — may,  of  course,  be  used  in  its 
original  state. 

SUGGESTIONS  AS  TO  THE  VALUE  OF  TESTS  AND  THE  MAN¬ 
NER  OF  TESTING  DRIERS  AND  JAPANS. 

All  tests  should  be  by  comparison;  no  test  that  is  not 
so  is  of  any  value. 

To  judge  any  drier,  japan  or  varnish,  it  should  be 
tested  side  by  side  (on  the  same  piece  of  glass,  if  pos¬ 
sible)  with  goods  whose  qualities  are  already  known. 

A  test  of  japan  or  drier,  in  its  natural  state,  may  not 
exhibit  its  true  properties.  No  drier  sets  and  dries  hard 
so  quickly  alone  as  “Lightning  Drier,”  and  none  con¬ 
tains  so  little  real  merit. 


146 


THE  MANUFACTURE  OF  LINSEED  OIL. 


TO  TEST  JAPANS. 


Use  a  clean  test  tube  or  bottle;  mix  the  article  to  be 
tested  with  raw  linseed  oil,  in  any  desired  proportion 
(one  part  drier  to  nine  parts  linseed  is  a  good  rule);  in 
a  similar  vessel  and  the  same  proportion,  mix  the  stand- 
dard  for  comparison;  agitate,  or  stir,  until  the  mixtures 
are  complete,  then  allow  to  stand  a  few  moments.  The 
two  compounds  may  then  be  tested  for  drying  strength, 
either  alone,  or  rubbed  up  in  any  desired  pigment.  Zinc 
IS  one  of  the  best  to  test  with  as  it  is  not  easy  to  dry. 

All  oil  driers  should  be  tested  in  a  similar  manner. 
In  some  cases  it  is  best  to  heat  the  materials  slightly 
in  mixing  oil  driers,  but  do  this  cautiously,  because  of 
the  turpentine  or  benzene  which  may  be  present. 

Boiled  linseed  oils  should  be  tested  pure  on  glass  and 
also  rubbed  up  in  lead  or  zinc,  and  always  in  compar¬ 
ison  with  another  oil 


OIL  BOILING. 


It  has  been  demonstrated  by  Mulder  that  linseed  oil 
is  a  glyceride  of  a  peculiar  acid  called  lineoleic  acid,  and 
according  to  a  recent  analysis,  lineoleic  acid  has  the  com¬ 
position  in  chemical  formula 


CisHsiOiOH; 


so  that  the  composition  of  the  glyceride  would  be  rep¬ 
resented  by 


Water,  mucilaginous  and  coloring  matter  abound  in 
the  crude  oil,  which,  together  with  the  lineoleic  acid  form 
its  component  parts.  The  primary  principle  incorpor¬ 
ated  in  practical  oil  boiling  is  the  elimination  of  the 
moisture  and  mucilaginous  matter  in  conjunction  with 
a  thorough  oxidation  of  the  oil. 

The  destruction  of  the  impure  substances,  and  com- 


THE  MANUFACTURE  OF  LINSEED  OIL. 


147 


plete  removal  of  the  moisture  present  in  all  crude  oil, 
are  of  necessity  an  essential  preparation  to  produce  a 
good  drying  oil.  It  has  been  shown  that  in  a  pure  oil, 
that  is  an  oil  made  from  full-grown  mature  seed,  tanked 
for  months,  in  order  to  procure  a  thorough  precipitation 
of  the  “footy”  or  objectionable  substances,  there  are 
twenty  parts  of  a  non-drying  nature.  This  proportion  is 
increased  when  the  oil  is  not  given  a  sufficient  length  of 
time  for  repose  and  in  the  ratio  to  the  quality  of  seed 
used.  This  fact  illustrated  the  necessity  of  efficient  oil 
boiling,  by  which  means,  in  conjunction  with  suitable 
driers  in  correct  proportions,  a  good  drying  oil  is  ob¬ 
tained.  Submitting  the  oil  to  an  intense  heat  has  the 
effect  of  destroying  the  glycerine  present,  the  non-dry¬ 
ing  qualities  of  which  render  it  unfit  for  economical  or 
practical  work.  This  destruction  is  materially  facilitated 
and  the  drying  properties  of  the  oil  increased  by  the  ad¬ 
dition  of  metallic  oxides  in  conjunction  with  heat, 
whether  by  the  direct  application  of  fire,  or  by  steam, 
and,  when  the  latter  method  is  used,  by  the  introduction 
of  air  into  the  mass  of  oil  in  the  treating  cauldrons.  Oil 
boiling  is  now  carried  on  with  much  greater  precision 
than  formerly. 

To  the  scientific  achievements  acquired  by  long  ex¬ 
perience,  this  desirable  result  is  attributable.  There  are 
various  methods  of  boiling,  each  having  a  stated  max¬ 
imum  and  minimum  degree  of  temperature,  to  procure 
a  certain  color  or  grade  of  oil. 

The  length  of  time  allotted  for  the  various  methods 
differs  largely,  whether  by  the  fire  or  steam  process.  As 
the  process  of  boiling  by  fire  has  right  of  priority  by 
reason  of  its  time-honored  usage,  we  shall  proceed  to 
treat  on  that  system  first.  The  oil  selected  for  boiling 
should  have  the  characteristic  color  of  pure  raw  linseed 
oil,  a  more  or  less  yellowish  green,  its  brightness  being 


148 


THE  MANUFACTURE  OF  LINSEED  OIL. 


a  guarantee  that  it  is  well  settled,  which  qualification  is 
only  acquired  by  being  left  for  a  considerable  period 
for  repose  in  the  settling  tank. 

SETTLING  TANKS. 

The  settling  tanks,  in  which  oil  is  placed  prepara¬ 
tory  to  be  being  boiled,  should  be  in  every  instance  cov¬ 
ered,  and  the  tanks  into  which  the  oil  is  pumped  after 
having  been  boiled,  should  be  also  covered,  as  a  pale 
color  is  not  so  much  an  object;  except  where  a  pale 
boiled  oil  is  especially  desired,  the  deprivation  of  oil  from 
light  is  of  no  consequence.  These  conditions  are  devised 
in  case  of  an  oil  prepared  for  white  lead  or  varnish  man¬ 
ufacture,  where  it  should  be  stored  as  much  as  pos¬ 
sible  exposed  to  the  light  in  order  to  bleach  it. 

Where  a  boiled  oil  is  stored  in  open  tanks  the  .oxygen 
and  surface  of  the  oil  combine  in  forming  a  thick  coat¬ 
ing  or  skin,  which  frequently  clogs  pipes,  and  in  some 
cases  is  drawn  off  in  fragmentary  portions  with  the  oil 
and  only  discovered  when  being  bleached  with  the  pig¬ 
ments  for  immediate  use.  As  previously  stated,  it  is 
of  the  utmost  importance  that  a  well-settled  oil  should 
be  chosen  for  the  reason  that  if  an  oil  be  used  which 
has  been  recently  made,  sufficient  time  not  being  allowed 
for  the  precipitation  of  the  plant  flesh  and  mucilaginous 
matter,  the  latter  becomes  charred,  which  in  turn  dis¬ 
colors  the  oil  when  subjected  to  the  high  temperature 
usual  in  fire  boiling,  rendering  it  of  an  inky  and  non¬ 
transparent  appearance,  not  only  at  the  conclusion  of 
the  boiling  operation,  but  for  a  permanency,  repose, 
however  prolonged,  being  inadequate  to  produce  a 
blight  oil.  Where  an  oil  is  chOsen  which  has  been  sub¬ 
jected  to  filtration,  immediately  after  being  made,  and 
prior  to  being  pumped  in  settling  tanks,  precipitation 
of  the  vegetable  matter,  together  with  its  anhydrous 


THE  MANUFACTURE  OF  LINSEED  OIL. 


149 


properties,  are  materially  facilitated.  It  is  a  well-known 
fact  that  a  certain  proportion  of  fine  plant  flesh  is  present 
in  all  ciude  oil,  notwithstanding  the  attention  bestowed 
in  the  matter  of  filtration,  repose,  etc.  The  specific  grav¬ 
ity  of  this  objectionable  substance  is  so  light  and  of  such 
similarity  in  its  density  to  that  of  the  oil  itself  that  it 
remains  suspended.  An  examination  of  a  sample  of 
such  oil,  when  subjected  to  the  first  test,  will  readily 
disclose  the  previously  invisible  substance.  The  more 
thorough  the  filtration  and  the  greater  the  period  of  time 
allotted  for  repose,  the  less  vegetable  matter  and  other 
impurities  will  be  necessary  to  be  eliminated  when  boil¬ 
ing,  thus  materially  aiding  that  process.  Where  it  is 
possible,  the  oil  selected  for  fire  boiling  should  be  per¬ 
mitted  a  longer  period  of  repose  than  that  which  is  cho.sen 
for  steam  boiling,  say,  several  weeks.  The  greater  the  heat 
an  oil  is  subjected  to,  the  darker  will  be  its  color;  so  that 
a  pure  oil  boiled  by  the  fire  process  will  be  much  darker 
than  that  boiled  by  the  steam  process;  therefore  the  ad¬ 
ditional  discoloration  consequent  upon  the  selection  of 

an  oil  for  fire  boiling  which  has  not  been  well  settled 

<» 

is  apparent,  and  should  be  carefully  guarded  against. 
Should  an  opaqueness  be  discernible  when  the  oil  is 
viewed  in  the  sample  glass,  however  slight,  it  should  be 
rejected;  it  is  an  indication  that  it  is  not  settled,  and 
therefore  contains  a  larger  proportion  of  moisture  and  of 
impure  substances  than  should  be  present  in  oil  for  boil¬ 
ing.  The  writer  has  seen  an  instance  where  an  oil  was 
boiled  a  few  hours  after  being  made,  which,  as  should 
have  been  known,  retained  its  inky  appearance,  and  gave 
the  consumer,  at  least  in  this  case,  solid  grounds  for 
complaint. 

To  sum  up:  The  indispensable  preliminary  treatment 
of  an  oil  for  boiling  is  simply  sufficient  time  for  re-. 


pose. 


150 


THE  MANUFACTURE  OF  LINSEED  OIL. 


A  fire-boiled  oil  may  be  said  to  be  efficiently  treated 
which  possesses  the  desired  color,  usually  a  deep  old 
port  wine  hue,  and  drying  properties,  which,  when  the 
oil  is  applied  in  a  thin  surface,  will  harden  and  become 
bright  and  glossy  in  from  five  to  seven  hours.  Imme¬ 
diately  after  a  parcel  of  oil  has  been  boiled  its  dry¬ 
ing  qualities  should  be  ascertained.  A  reliable 
method  of  accomplishing  this  is  to  cover  the  surface 
of  a  small  piece  of  glass  thinly,  placing  the  latter  in  a 
vertical  position  against  some  object,  and  if  at  the  end 
of  six  or  seven  hours  it  shall  present  a  dried  and  uni¬ 
formly  glossy  surface,  it  may  be  classed  as  a  good  boiled 
oil. 

If,  on  the  other  hand,  the  upper  part  of  the  glass  is 
greasy  and  tacky  to  the  touch,  the  lower  being  covered 
with  a  heavier  body  of  the  oil,  which  has  slowly  worked 
down  in  streaks,  it  is  an  indication  that  it  is  an  im¬ 
perfectly  boiled  oil. 

This  method  resembles  Messrs.  Pratt’s  paper  rule,  but 
as  glass  is  a  slower  test  the  result  is  more  reliable. 

Extreme  care  is  essential  to  maintain  a  uniform  heat 
in  the  oil  when  boiling.  The  usual  temperature  for  fire 
boiling  averages  between  500°  Fahrenheit  and  600° 
Fahrenheit.  By  means  of  the  proper  fuel,  with  the  other 
necessary  appliances,  this  heat  can  be  steadily  main¬ 
tained  without  serious  fiuctuation  for  several  hours.  The 
exact  temperature  can  be  accurately  ascertained  at  any 
stage  of  the  process  by  a  glance  at  the  elongated  ther¬ 
mometer  suspended  in  the  oil. 

The  utility  of  the  thermometer  is  apparent,  as  any 
sudden  change  in  the  temperature  is  at  once  perceived 
by  the  oil  boiler  and  the  neces.sary  remedy  applied 
promptly.  If  the  thermometer  should  suddenly  rise 
when  in  the  proximity  of  550°  Fahrenheit,  imminent 
danger  is  present  of  its  swelling  and  running  over  the 


THE  MANUFACTURE  OF  LINSEED  OIL. 


151 


lop  of  the  kettle,  in  which  case  a  prompt  withdrawal  of 
the  fire  with  cold  oil  poured  in  will  avert. 

This  action  of  the  mercury  would  indicate  that  a  regu¬ 
lar  fire  had  not  been  maintained,  or  the  difficulty  may 
have  arisen  from  the  nature  of  the  oil.  Oil  made  from 
Ea.st  India  seed  has  a  tendency  to  swell  and  froth  when 
subjected  to  heat,  consequently  is  more  dangerous  in 
boiling. 

just  now,  however,  when  there  is  such  a  material 
difi’eronce  in  the  relative  values  of  the  oil  from  the  for¬ 
eign  and  that  from  the  domestic  seed,  the  former  com¬ 
manding  a  higher  commercial  value,  it  is  rarely,  if  ever 
used  for  boiling. 

If,  on  the  contrary,  the  mercury  descends  in  the  tube, 
the  fire  needs  prompt  attention  by  being  increased  in  in¬ 
tensity. 

The  modern  system  of  oil  boiling  in  efficiency  and  pre¬ 
cision  becomes  more  apparent  when  compared  with  the 
old  rule  of  thumb  method  in  vogue,  when  the  only  sys¬ 
tem  known  was  that  of  submitting  the  oil  with  a  certain 
proportion  of  red  lead  to  an  unknown  temperature,  the 
entire  operation  being  gauged  by  the  individual  fiat  of 
the  crude  oil  boiler.  Boiling  linseed  oil  with  chemical 
compounds  added  thereto  and  known  as  driers,  facili¬ 
tates  the  thorough  diffusion  of  the  latter  throughout  the 
mass  by  imparting  to  it  the  oxygen  absorbing  and  dry¬ 
ing  jjroperties  which  are  characteristic  features  of  the 
combination  of  lead  salts  and  manganese  known  as 
litharge,  acetate  of  lead,  sulphate  of  lime,  and  other 
basic  lead  oxides. 

To  the  painter,  the  thoroughness  of  oil  boiling  is  of 
peculiar  consequence. 

Pure  linseed  oil,  well  boiled  in  conjunction  with  a 
judiciously  selected  drier,  correct  in  quality  and  propor¬ 
tion,  possesses  the  requisites  absolutely  indispensable 


152 


THE  MANUFACTURE  OF  LINSEED  OIL. 


to  form  a  good  covering  surface  as  the  component  part 
of  an  applied  paint.  A  good  boiled  oil  should  not  run 
into  streaks,  leaving  remnants  of  the  coloring  matter  be¬ 
hind,  but  should  form  a  smooth,  but  hard  surface,  im- 
liermeable  for  a  prolonged  period  to  atmospheric  in¬ 
fluences.  This  is  what  practically  constitutes  a  good 
boiled  oil.  A  uniform  system  of  boiling  all  varieties  of 
linseed  oil  would  be  inapplicable.  A  pure,  well  settled 
oil  made  from  ripe  seed,  containing  a  small  proportion 
ot  natural  moisture,  does  not  require  as  much  drier  or 
as  long  a  period  for  boiling,  as  an  oil  made  from  a 
stunted  and  impoverished  seed.  The  treatment  neces¬ 
sary  to  the  latter,  if  applied  to  the  former,  would  spoil 
the  entire  batch.  Oil  from  inferior  seed  should  be  per¬ 
mitted  a  much  longer  period  for  settling,  and  when  boil¬ 
ing,  more  drier  and  longer  time  is  necessary. 

Red  lead  and  umber  are  used  in  boiling  by  fire,  both 
ingredients  imparting  color  to  the  oil.  Red  lead  pos¬ 
sesses  powerful  drying  properties,  materially  oxidizing 
the  oil,  as  well  as  imparting  color  to  it,  but  it  has  been 
largely  superseded  within  recent  years,  and  it  is  not  used 
so  extensively  as  formerly.  Umber  is  not  used  to  the 
extent  it  formerly  was,  but  old  oil  boilers  •  have  great 
faith  in  its  virtues.  It  contains  a  certain  proportion  of 
manganese  and  alumina,  about  12  per  cent  of  the  for¬ 
mer  and  2  per  cent  of  the  latter,  the  properties  of  which 
are  so  essential  to  a  good  drying  oil.  It  also  imparts  a 
rich  hue  to  the  oil,  some  consumers  basing  their  esti¬ 
mate  on  the  quality  of  the  oil  by  this  color.  It  is,  there¬ 
fore,  apparent  that  umber  is  a  good  coloring  agent  and 
contains  elements  in  the  form  of  manganese  and  alu¬ 
mina,  which  if  carefully  ground,  is  valuable  in  propor¬ 
tion  to  the  above  properties  it  contains.  It  also  imparts 
a  good  body  to  the  oil  and  thoroughly  assimilating 
with  it. 


I 


THE  MANUFACTURE  OP  LINSEED  OIL. 


153 


The  following  are  the  names  of  the  chemicals  used 
as  driers  in  various  proportions:  litharge,  lead  acetate 
or  sugar  of  lead,  manganese  dioxide,  sulphate  of  zinc, 
red  lead,  umber,  borax,  etc.,  etc. 

Driers  of  the  metallic  nature  usually  aggregate  in 
weight  when  used  in  the  oil  from  five  to  eight  pounds 
for  each  300  gallons.  Prof.  Hurst  states  that  litharge 
is  the  monoxide  of  lead  and  has  the  composition  shown 
by  the  formula  PbO.  Mixed  with  drying  oils,  a  slow 
action  sets  in,  resulting  in  the  formation  of  lead  soaps 
which  are  insoluble  in  water  and  many  solvents.  This 
action  occurs  with  linseed  oil.  The  lead  linoleate  so 
formed  dissolves  in  the  rest  of  the  oil,  forming  a  kind  of 
varnish,  which,  on  drying,  forms  a  lustrous  coat.  This  is 
a  marked  feature  of  lead  salts,  which  renders  their  use 
of  especial  value  to  the  oil  boiler.  Litharge  being  a 
powerful  drier,  it  should  be  borne  in  mind  that  it  should 
not  be  used  extravagantly  in  oil  boiling,  but  in  the  pro¬ 
portion  of  about  ten  pounds  to  the  ton  of  oil.  Sugar  of 
lead  or  acetate  of  lead  has  not  the  drying  or  oxygen 
imparting  qualities  which  are  features  of  litharge,  man¬ 
ganese,  or  red  lead,  but  when  added  to  the  oil  in  cor¬ 
rect  proportions,  readily  assimilates  without  discoloring 
it.  The  latter  qualification  renders  its  use  desirable 
where  a  pale  boiled  oil  is  needed.  The  black  oxide  of 
manganese  is  the  most  powerful  of  all  driers,  and  is  now 
extensively  used.  It  possesses  a  greater  proportion  of 
oxygen  than  any  other  drier,  which  feature  renders  it 
invaluable  for  oil  boiling.  When  added  to  the  oil,  and 
the  proper  temperature  arrived  at,  a  small  proportion  of 
its  weight  dissolves  slowly,  the  whole  transmitting  to  the 
mass  its  oxidizing  or  drying  properties,  and  the  residue 
precipitating  the  moment  the  mechanical  agitation  in 
the  boiling  caldron  ceases.  The  precipitated  manga¬ 
nese  matter  has  the  peculiar  faculty  of  re-absorbing  the 


154 


THE  MANUFACTURE  OF  LINSEED  OIL. 


element  which  it  has  in  part  lost  during  the  boiling  pro¬ 
cess.  By  proper  treatment,  it  will  again  absorb  oxygen 
and  become  as  powerful  a  drier  as  before.  A  formula 
will  be  described  later  on  by  the  observance  of  which  the 
once-used  manganese  can  be  restored  to  its  pristine  use¬ 
fulness.  The  proportion  of  this  drier  used  should  not 
exceed  six  pounds  to  a  ton  of  oil.  A  greater  amount 
would  not  only  darken  the  oil,  but  would,  when  the  lat¬ 
ter  is  applied  as  the  constituent  part  of  a  paint,  mate¬ 
rially  afifect  the  surface,  cracking,  and  proving  unsatis¬ 
factory  generally.  Its  drying  qualifications,  under  such 
conditions,  are  all  that  could  be  desired,  but  the  excess 
of  manganese  deteriorates  the  durability  of  the  paint,  to¬ 
gether  with  imparting  a  rough  surface  to  the  whole,  by 
reason  of  its  cracking  and  separating.  Sulphate  of  zinc, 
which  is  commonly  used  in  this  country,  is  considered  by 
some  chemists  to  be  of  little  value,  its  virtues  as  a  drier 
being  problematical. 

The  prevailing  opinion  among  oil  boilers  in  Europe, 
as  well  as  in  the  United  States,  in  regard  to  the  inherent 
properties  of  sulphate  of  zinc,  is,  that  when  added  to  the 
oil  at  the  proper  moment,  and  a  high  degree  of  tem¬ 
perature  has  been  reached,  it  renders  the  impurities — 
mucilaginous  substances,  etc. — insoluble,  and  thus,  by 
increasing  their  specific  gravity,  aided  by  the  charring 
effects  of  the  heat,  hastens  their  precipitation  after  the 
boiling  process  has  ceased.  Its  action  in  this  respect 
is  co-incident  with  that  of  sulphuric  acid,  when  a  crude 
oil  is  being  manipulated  for  white  lead  or  varnish  manu¬ 
facturing. 

Livache,  in  investigating  the  process  of  oxidation  of 
drying  oils,  has  shown  that  when  treated  with  metallic 
lead,  or  with  litharge,  and  shaken  up  with  a  solution 
of  zinc  sulphate,  all  the  lead  is  precipitated  from  the  oil 
and  the  zinc  passes  into  solution  therein. 


THE  MANUFACTURE  OF  LINSEED  OIL. 


155 


It  has.  however,  been  demonstrated  that  the  action 
of  salts  of  zinc  exerts  no  chemical  action  on  the  drying 
(lualities  of  the  oil  when  cold,  but  when  added  thereto 
nt  the  seasonable  moment  and  the  increasing  tempera¬ 
ture  slowly  proceeds,  its  action  on  the  suspended  impuri¬ 
ties  is  believed  by  many  to  hasten  their  destruction,  thus 
materially  increasing  the  drying  qualities  of  the  oil. 
Buckheister  shows  that  zinc  linoleate  and  lead  linoleate 
do  not  act  as  driers  when  simply  added  to  the  oil;  he 
has  also  shown  that  though  the  former  is  soluble  in 
heated  oil,  it  is  insoluble  in  cold  oil,  and  it,  therefore, 
separates  from  the  oil  as  it  cools. 

The  exact  action  of  lead  salts  is,  however,  somewhat 
uncertain,  but  it  may  be  accepted  that  to  a  certain  ex¬ 
tent  they  tend  to  precipitate  the  impure  substances,  caus¬ 
ing  the  oil  in  co-operation  with  the  heat,  to  become  more 
fluid  at  the  time  of  boiling,  thus  facilitating  the  precipi¬ 
tation  of  the  impure  matter  when  in  repose  and  impart¬ 
ing  to  the  whole  a  good  body. 

The  function  which  borax  performs  is  of  the  absorption 
of  muriatic  and  sulphurous  gases,  but  no  others,  and  it 
promotes  a  fusion  of  the  other  ingredients. 

Reference  has  been  made  to  the  peculiar  quality  of 
manganous  oxide  by  means  of  which  the  elements  which 
it  has  been  deprived  of  can  be  restored.  In  Europe  the 
practice  of  restoring  the  oxygen  to  the  already  utilized 
manganese  is  common.  The  precipitated  matter  is  taken 
from  the  bottom  of  the  boiling  caldron  and  burned  in 
the  furnace  until  the  vestige  of  chemical  and  fatty  mat¬ 
ter  is  destroyed.  It  is  then  placed  in  an  exposed  place, 
spread  efut  thinly,  so  that  as  much  as  possible  of  the 
pulverized  metal  will  be  accessible  to  the  atmosphere  and 
left  for  a  period  extending  from  four  to  twelve  months, 
when  it  can  be  again  used  to  as  much  advantage  as  be- 


m 


Tll£  MANtlfACTURE  0£  LiNSEEt)  OIL. 


■fore.  This  process  can  be  repeated  for  a  nnnil^er  of  times 
before  the  utility  of  the  manganese  shall  have  ceased. 

In  many  oil  boiling  establishments  in  Europe,  and  in 
several  in  the  United  States,  the  precipitated  manganese 
is  again  used,  with  the  addition  of  fresh  material  and  with¬ 
out  exposure  to  the  atmosphere.  It  is  well  known  that 
after  having  passed  the  boiling  process,  it  still  contains 
a  proportion  of  oxygen  which  is  further  utilized  in  con¬ 
junction  with  the  new  material,  as  has  already  been 
stated. 

A  GOOD  DRIER  FORMULA. 

The  writer  has  frequently  made  a  drier  in  the  follow¬ 
ing  proportions  for  fire-boiled  oil  with  satisfactory  re¬ 
sults  : 

About  80  gallons  of  clear  raw  oil  are  poured  into  the 
drier  caldron  and  gradually  heated.  When  the  first 
froth  or  effervescence  subsides.,  the  following  ingredients 
are  slowly  added:  20  pounds  of  manganese,  4  pounds  of 
red  lead,  and  2  pounds  of  sulphate  of  zinc.  This  is 
boiled  for  the  space  of  3^  or  4  hours,  or  until  the  whole 
shall  have  assumed  a  sirupy  condition.  Great  care  is 
required  to  guard  against  the  mixture  boiling  over,  in 
the  event  of  which  disastrous  results  will  ensue. 

There  is  great  danger  attached  to  drier  making,  and 
unremitting  care  is  needed  to  establish  a  uniform  heat 
during  the  entire  process,  and  a  close  watch  kept  on 
the  action  of  the  contents  of  the  boiling  pot. 

The  mass  must  be  constantly  agitated  by  two  attend¬ 
ants  provided  with  paddles,  which  alternately  sweep 
around  the  bottom  and  sides  of  the  pot,  thus  distribut¬ 
ing  the  heat  more  uniformly  and  rendering  the  admix¬ 
ture  and  assimilation  of  the  chemicals  with  the  oil  more 
perfect.  The  fire  is  now  withdrawn,  and  the  drier  ready 
for  use  proportionate  to  the  grade  of  oil  required. 

We  now  proceed  to  use  the  precipitated  manga- 


THE  MANUFACTURE  OF  LINSEED  OlL. 


157 


nese,  when  the  following  course  is  pursued:  After  hav¬ 
ing  emptied  the  kettle  of  its  contents  in  the  matter  of 
drier,  which  is  conveyed  to  a  proper  receptacle  for  future 
use,  the  precipitated  manganese,  with  the  lead  and  other 
chemical  and  sooty  matter,  is  not  removed,  and  80  gal¬ 
lons  of  new  oil  added  thereto,  which  in  conjunction 
with  the  following  proportion  of  new  driers,  and  operated 
exactly  similar  to  the  one  described  is  repeated.  Ten 
pounds  of  new  manganese,  2  pounds  of  red  lead,  and  1 
pound  of  sulphate  of  zinc,  gradually  added,  will  make  as 
serviceable  a  drier  boiled  with  the  residue  of  the  first 
process  as  the  latter  under  similar  conditions.  Another 
combination  of  driers  which  has  proved  satisfactory  in 
turning  out  an  oil  suitable  for  all  practical  work,  is  made 
as  follows:  Twenty-four  gallons  of  crude  oil  are  placed  in 
the  drier  pot  and  heat  slowly  applied,  when  30  pounds 
of  manganese,  5  pounds  sugar  of  lead  (or  acetate  of  lead), 
3  pounds  of  borax  and  about  2  pounds  of  sulphate  of 
zinc,  are  slowly  added,  the  whole  being  in  a  state  of 
commotion  the  while.  The  same  precautionary  measures 
are  necessary  as  in  the  previous  operation,  two  attend¬ 
ants  being  required  to  be  paddling  the  mixture  without 
exertion  until  the  process  is  completed..  The  three  latter 
ingredients  must  be  added  in  small  cjuantities  so  that  the 
whole  will  be  thoroughly  mixed,  the  agitation  being 
kept  up  until  the  drier  is  made,  and  for  the  space  of  one- 
half  an  hour  after  the  fire  is  withdrawn,  when  cooling 
sets  in. 

In  addition  to  the  above,  a  few  gallons  of  raw  oil 
poured  in  from  time  to  time,  especially  if  the  mass  at  any 
stage  of  the  process  attempts  to  swell  or  rise.  This  has 
the  effect  of  causing  it  to  subside  at  once,  and  should  be 
used  in  the  proportion  necessary  to  bring  the  mixture  to 
the  consistency  of  thick  molasses. 

When  a  drier  pot  is  emptied  it  should  be  thoroughly 


158 


THE  MANUFACTURE  OF  LINSEED  OIL. 


scraped  and  cleaned;  the  sides  and  the  bottom,  especially 
shall  be  divested  of  any  metallic  scaling-  adhering  to  it. 

lloiling  oil  by  the  aid  of  this  drier  is  usually  carried  on 
as  follows:  The  full  amount  of  drier  made  by  the  last 
described  method  would  be  sufficient  for  ordinary  pur¬ 
poses,  to  be  added  to  from  1,200  to  1,500  gallons  of  oil. 
The  quantity  cf  drier  made  at  a  single  operation,  or  the 
amount  of  oil  boiled,  varies  in  proportion  to  the  capacity 
and  number  of  pots  used. 

In  the  case  of  the  latter,  a  row  of  pots  of  boiling  oil 
can  be  properly  attended  to  by  two  persons,  which  would 
be  impossible  in  the  case  of  drier  making. 

From  1,000  to  8,000  gallons  of  oil  are  boiled  at  one  time. 

The  usual  course  of  procedure  consists  in  first  starting 
the  fires  after  the  oil  has  been  placed  in  the  pots  and 
slowly  heated.  When  the  temperature  has  reached  that 
point  that  when  the  finger  is  placed  in  the  oil  it  becomes 
painful,  the  drier  is  slowly  poured  in.  The  oil  is  then 
frequently  stirred  by  the  attendants  until  the  process  is 
completed.  In  some  large  concerns  a  driving  or  agitat¬ 
ing  gear  is  operated  by  a  separate  engine,  as  in  the  case 
of  steam-boiled  oil.  The  revolving  motion  of  the  vertical 
shaft  running  down  the  centre  of  the  kettle  with  the  ex¬ 
tended  arms  attached  works  well,  and  much  more  uni¬ 
formly  than  when  the  agitation  is  dependent  on  the 
muscles  of  the  attendants.  The  entire  mass  is  thor¬ 
oughly  mixed;  the  revolutions  of  the  agitators  should 
not  exceed  four  or  four  and  one-half  per  minute. 

The  quality  of  the  oil  will  largely  depend  on  the  uni¬ 
formity  of  the  heat  applied,  any  fluctuations  having  a 
tendency  to  spoil  the  batch.  The  process  should  not  be 
terminated  under  5^  hours,  the  temperature  averaging  as 
nearly  as  possible  about  55°  Fahrenheit. 

Where  the  fires  are  withdrawn,  a  certain  proportion  of 
red  lead  (about  10  pounds  usually)  is  added  to  the  oil, 


THE  MANUFACTURE  OF  LINSEED  OIL. 


i:.9 


but  sometimes  in  amounts  sufficient  to  procure  the  de¬ 
sired  color.  The  capacity  of  the  boiling  pots  varies  from 
200  to  1,000  gallons,  and  sometimes  even  a  larger  vessel 
is  used. 

In  formation  they  should  be  about  the  same  depth  and 
breadth.  As  the  heat  strikes  the  bottom  of  the  pot  with 
more  or  less  intensity,  the  metal  will  contract  or  expand 
if  the  temperature  is  changed  rapidly,  thus  causing 
cracks,  and  rendering  the  pot  unfitted  for  further  work. 

For  a  slight  additional  cost,  extra  thick  bottoms  can 
be  made  when  casting,  and  with  ordinary  care  will  last 
with  regular  use  for  many  years. 

Some  boiling  pots  are  made  in  France  and  England  of 
wrought-iron  boiler-plates  of  a  uniform  thickness,  and 
the  bottom,  which  is  made  separate,  is  riveted  to  the 
outer  sides.  By  a  sy. stern  of  fines  encircling  the  boiling 
pot,  heat  can  be  more  evenly  distributed,  thus  avoiding 
the  infringement  of  the  intense  heat  on  any  particular 
spot,  and  lessening  its  liability  to  crack. 

Where  the  quantity  of  oil  boiled  at  a  single  operation 
in  one  large  caldron  amounts  to  1,(M)()  gallons,  the  sys¬ 
tem  before  alluded  to,  having  a  driving  gear,  should  be 
adopted.  The  commingling  of  the  mass  is  better  per¬ 
formed,  and  fusion  is  thus  materially  facilitated.  Where 
circumstances  permit,  a  flagged  floor  having  a  slight 
pitch  towards  the  door  of  the  building  or  shed  should  be 
constructed,  extending  around  the  pot,  and  between  the 
top  of  the  latter  and  the  furnace  beneath,  thus  effectively 
shutting  off  all  chances  of  the  oil,  should  it  flow  over, 
coming  in  contact  with  the  fire  beneath.  By  this 
means  the  boiling  can  be  carried  on  with  comparative 
safety,  the  risk  of  conflagration  being  entirely  removed. 
As  an  additional  precautionary  measure,  the  oil  boiler 
should  have  at  hand  40  or  bO  gallons  of  the  raw  oil, 
so  that  any  suspicious  movement  of  the  oil  could  be 


160 


THE  MANUFACTtJRR  OF  LINSEED  OIL. 


immediately  checked  by  pourings  a  quantity  in  and  then 
promptly  withdrawing  the  fire.  Sufficient  room  should 
be  left  between  the  surface  of  the  body  of  oil  and  the  top 
of  the  boiling  pot  to  prevent  any  slight  swelling  or  effer¬ 
vescence  from  causing  the  mass  to  flow  over. 

By  a  system  of  weights  and  movable  sheet-iron  hoods 
which  descend  and  completely  cover  the  pot  when  the 
boiling  operation  is  progressing,  the  operative  is  spared 
the  suffering  of  inhaling  the  pungent  vapors  of  the 
seething  mass.  These  hoods  are  connected  by  means 
of  a  large  pipe  with  the  main  chimney  of  the  steam 
boiler  furnaces,  and  the  abominable  odor  is  thus  con¬ 
veyed  into  the  atmosphere.  In  some  instances  where 
oil  boiling  is  carried  on  in  the  centre  of  a  large  city,  the 
vapor  is  drawn  to  the  boiler  furnaces  and  passed  through 
the  fires,  thus  completely  destroying  them  by  the  in¬ 
tense  heat  before  reaching  the  atmosphere. 

The  flying  and  obnoxious  vapors  which  would  other¬ 
wise  linger  in  the  vicinity  where  oil  boiling  is  carried  on, 
attacking  the  eyes  and  the  lungs  of  all  coming  within 
reach,  rendered  the  adoption  of  this  method  an  abso¬ 
lute  necessity  in  populous  centres. 

The  hoods  alluded  to  have  at  their  lower  extremity, 
and  at  various  places  around,  small  doors  or  hatchways, 
which  open  and  shut  by  means  of  hinges,  so  that  the  oil 
boiler  can  at  any  time  observe  the  action  beneath;  these 
small, doors  also  give  sufficient  room  for  the  working  of 
the  paddles,  where  such  are  used,  and  which  can  be 
worked  when  the  hood  is  closed  all  around. 

It  may  be  stated  that  in  the  event  of  the  oil  boiling 
over,  where  no  intervening  floor  is  placed  between  the 
top  of  the  pot  and  the  furnace  fires,  no  better  means  can 
be  adopted  in  such  an  emergency  than  by  throwing 
sand  on  the  burning  fluid.  For  this  reason,  it 
is  always  desirable  to  have  an  available  supply 


THE  MANUFACTURE  OF  LINSEED  OIL. 


161 


of  sand  on  hand  where  the  boiling  is  done  in 
the  above  manner.  Where  oil  is  in  conflagra¬ 
tion,  water  should  be  studiously  avoided;  its  use 
would  bring  about  ten-fold  more  trouble.  In 
some  methods  of  oil  boiling  by  fire,  and  in  drier  mak¬ 
ing  especially,  risks  are  taken  of  necessity,  so  that  every 
possible  precaution  should  be  taken  to  avert  a  conflag¬ 
ration,  and  when  such  should  occur,  the  means  referred 
to  should  be  readily  available  to  effect  the  extinction  of 
the  flames  of  the  burning  oil.  In  some  large  European 
boiling  concerns,  the  large  pots  are  completely  bricked  in 
with  arched  covering,  the  agitating  shaft  descending 
through  a  stuffing  box  in  the  arch,  placed  immediately 
over  the  centre  of  the  spot,  and  in  the  event  of  the  oil 
rising  over  the  pot,  it  could  only  flow  through  one  small 
opening,  the  burning  fluid  being  conveyed  by  means  of 
a  large,  shallow  iron  trough  well  out  into  the  open  at¬ 
mosphere. 

Having  described  the  method  of  oil  boiling  by  fire,  we 
now  come  to  the  steam  boiling  process  which  is  in  use 
in  many  parts  of  the  United  States.  Oil  boiled  by  fire 
in  conjunction  with  lead  salts  is  detrimental  to  good 
work  when  mixed  with  zinc  white.  It  is  only  due  in  part 
to  this  fact  that  the  idea  of  boiling  by  steam  was  first  for¬ 
mulated  shortly  after  the  introduction  of  the  latter  as  a 
pigment.  However,  the  desire  to  avoid  the  odors  when 
oil  is  boiling  (the  effective  methods  which  have  been  de¬ 
scribed  for  the  destruction  of  these  vapors  and  odors 
were  unknown  at  the  period  of  the  introduction  of  the 
steam  boiling  system)  has  doubtless  played  an  import¬ 
ant  part  in  the  new  departure.  Sufficient  heat  can  be 
imparted  to  the  oil  by  this  means  to  drive  off  the  hydro¬ 
genous  conditions  present,  and,  by  its  prolongation,  with 
the  addition  of  suitable  driers,  drying  and  hardening 
qualities  are  superinduced. 


1G2 


THE  MANUFACTURE  OF  LINSEED  OIL. 


There  are  decided  advantages  in  using  steam  as  a 
means  of  boiling  oil;  the  risk  of  fire  is  reduced,  and  the 
oil  is  in  accordance  with  the  nature  of  the  drier  used, 
much  lighter  in  color.  Colorless  driers,  such  as  acetate 
of  lead  in  solution,  being  largely  used,  and  in  proportion 
to  the  color  and  general  qualities  required.  For  very 
many  purposes  an  oil  boiled  by  steam  is  equally  as  good 
as  that  boiled  by  fire,  while  for  special  work  its  proper¬ 
ties  with  regard  to  light  color,  etc.,  are  indispensable, 
the  latter  feature  being,  as  is  well  known,  entirely  for¬ 
eign  to  the  fire-boiled  oil. 

The  steam  jacketed  kettle  in  which  the  oil  is  treated 
has  various  forms  and  sizes,  but  a  brief  description  of 
one  will  give  a  general  idea  of  the  design  of  all.  Through 
the  centre  of  the  domed  kettle  a  shaft  descends,  hav¬ 
ing  projecting  arms  and  serving  the  same,  purpose  when 
in  motion  as  that  which  has  been  previously  described. 
Pipes  are  connected  to  the  top,  and  run  to  the  furnaces 
or  chimney  as  described,  and,  as  before  described,  when 
treating  on  the  fire-boiled  system.  By  this  means  the 
odors  and  vapors  are  similarly  removed. 

Through  the  jacketed  bottom  a  pipe  is  laid  and  ex¬ 
tended  across  the  entire  bottom  of  the  kettle. 

By  means  of  this  pipe,  which  is  thickly  perforated 
with  small  holes,  finely  divided  currents  of  air  are  forced 
into  the  oil.  This  has  a  tendency,  in  conjunction  with 
the  drier  used,  to  oxidize  and  impart  a  body  to  the  oil,  as 
Avell  as  keeping  the  mass  in  constant  commotion  in  co¬ 
operation  with  the  heat.  In  some  instances  circular  coils 
of  air  piping  are  arranged  around  the  bottom  of  the  ket¬ 
tle.  A  blowing  engine  supplies  and  forces  the  air 
through  during  the  entire  process.  The  heat  applied 
varies  from  35  to  40  pounds  of  steam  pressure  per  square 
inch  on  the  kettle.  In  some  instances  the  oil  before  be¬ 
ing  pumped  into  the  treating  kettle  is  heated  prelimin- 


THE  MANUFACTURE  OF  LINSEED  OIL. 


163 


arily  by  means  of  a  steam  coil  and  np  to  200  or  210 
cubic  feet.  This  preliminary  heating  greatly  facilitates 
the  boiling.  The  jacketed  portion  is  two-thirds  of  the 
size  of  the  kettle. 

By  the  means  described,  ample  facilities  are  afforded 
to  produce  a  good  boiled  oil.  The  quantity  of  driers 
does  not  equal  in  weight  that  which  is  used  by  the  fire¬ 
boiling  system.  It  is  frequently  added  in  fluid  form,  and 
the  perfect  system  of  uniform  heat  and  agitation 
by  steam  and  air,  procures  as  thorough  a  diffusion  of 
oil  and  drier  as  can  be  achieved,  bringing  the  particles 
into  intimate  contact  with  each  other,  and  at  the  same 
time  thoroughly  oxidizing  the  oil.  Prof.  Hurst  describes 
the  method  of  procuring  a  drying  oil  recently  patented. 

A  manganese  linoleate  is  made  by  preparing  a  soap  of 
linseed  oil  by  the  following  process:  The  manganese 
linoleate  is  dissolved  in  twice  its  weight  of  turpentine 
and  from  two  to  five  volumes  of  this  solution  are  added 
to  100  volumes  of  linseed  oil.  Insoluble  matters  are 
separated,  the  mass  raised  to  a  temperature  of  212'' 
Fahrenheit  in  a  special  apparatus,  and  a  current  of  air 
or  oxygen  passed  through  the  oil  until  it  has  attained 
the  desired  degree  of  thickness;  for  example,  a  clear, 
transparent  oil  of  a  pale  amber  color,  having  a  specific 
gravity  of  0.007,  can  be  obtained  from  a  linseed  oil  of 
specific  gravity  0.037.  This  thickened  oil  may  be  used 
in  painting,  and  in  the  manufacture  of  floor  cloth, 
linoleum  and  similar  materials.  It  must,  however,  be 
borne  in  mind  that  this  especial  treatment  only  refers  to 
oil  from  East  India  seed. 

Mulder  found  that  when  raw  oil,  especially  if  old,  was 
kept  for  twelve  or  eighteen  hours  at  a  temperature  of 
100°  Fahrenheit,  it  acquired  the  property  of  boiled  oil. 

According  to  C.  W.  Vincent,  a  body  of  oil  heated  so 
that  no  air  can  reach  it  except  on  the  surface,  as  in  a 


164 


THE  MANUFACTURE  OF  LINSEED  OIL. 


jacketed  kettle;  such  oil  heated  for  several  days  became 
thicker,  more  greasy,  and  had  decidedly  less  drying 
power,  and  out  of  many  hundreds  of  samples  taken  at 
various  stages  of  heating  and  boiling,  not  one  dried 
more  rapidly  than  a  sample  of  raw  oil  from  which  it  had 
been  taken. 

Between  these  conflicting  results,  an  intermediary 
course  is  pursued  which  is  productive  of  a  pale  boiled 
oil.  The  application  of  heat  is  only  permitted  to  a 
limited  extent  in  conjunction  with  a  suitable  colorless 
drier.  In  some  instances  the  light  colored  fluid  drier 
is  simply  mixed  with  the  oil  for  a  short  period  without 
the  application  of  heat. 

When  the  operation  has  terminated  in  the  fire-boil¬ 
ing  system,  where  it  is  possible  the  oil  should  be  allowed 
to  remain  in  the  pot  for  at  least  forty-eight  hours.  This 
gives  ample  time  for  cooling  and  precipitation  of  the 
footy  matter.  The  longer  the  period  of  repose  in  the 
boiling  pot,  the  better  and  more  thoroughly  the  sus¬ 
pended  impurities  will  descend  in  conjunction  with  the 
fine  metallic  particles. 

After  an  oil  has  been  boiled,  whether  by  the  fire  or 
steam  process,  it  is  not  necessary  to  subject  it  to  filtra¬ 
tion;  three  or  four  weeks’  repose  in  the  settling  tanks 
prior  to  shipment  is  all  that  is  necessary. 


The  Filter  Press  in  Oil  Milling— Further  Details  Concerning 

Its  Workings,  Etc. 


The  introduction  of  the  filter  press  marks  a  new  era 
in  modern  oil  milling.  In  many  of  the  industrial  arts, 
especially  those  which  require  the  separation  of  solids 
from  liquids  when  held  in  suspension,  the  work  was  here¬ 
tofore  accomplished  by  the  hydraulic  press  or  centrifugal 
machine,  and,  according  to  the  nature  of  the  work,  by 
evaporation  and  concentration;  the  filter  press  has 
relegated  all  these  among  the  things  of  the  past.  Its 
adaptation  to  the  special  requirements  of  chemical  and 
color  works,  paraffine  wax,  china  clays,  stearine,  dex¬ 
trine,  yeast,  paper,  whiting,  plaster,  sugar,  graphite,  etc., 
has  been  most  momentous.  In  every  art  where  filtra¬ 
tion  or  percolation  is  brought  into  requisition  in  the 
various  manufacturing  processes  it  has  proved  of  the 
greatest  value.  In  the  clarification  of  liquors,  such  as 
linseed,  cottonseed,  lard  and  castor  oils,  glycerine,  var¬ 
nish,  chocolate,  water,  ink,  chemical  and  pharmaceuti¬ 
cal  preparations,  it  is  widely  used.  For  extracting  and 
washing  powdery  substances,  as  in  the  manufacture  of 
bicarbonate  of  soda,  cream  of  tartar,  etc.,  its  efficiency 
is  recognized.  Hot  presses  for  wax  and  candle  manu¬ 
facturing,  and  close  filtration  presses,  in  which  naphtha, 
alcohol,  ether  or  other  volatile  fluids  are  used,  are  also 
in  general  use.  Some  of  these  latter  are  of  great  size, 
the  plates  being  set  together  by  means  of  hydraulic 
pressure. 

Although  of  comparatively  recent  origin,  its  wide¬ 
spread  recognition  as  an  invaluable  factor  in  the  ad¬ 
vancement  of  the  respective  arts  where  its  use  becomes 
practicable  is  abiding.  Its  utility  has  been  demon¬ 
strated  by  a  decade  of  practical  experience,  and  owing  to 

105 


166 


THE  MANUFACTURE  OF  LINSEED  OIL. 


the  general  approval  with  which  its  functions  are  re¬ 
garded,  the  wonder  is  that  this  latest  and  most  important 
innovation  in  many  of  the  manufacturing  industries  was 
so  long  deferred. 

To  the  oil  miller  and  varnish  maker  the  filter  press  is 
of  peculiar  consequence.  No  well  regulated  and 
equipped  mill  can  afford  to  di.spense  with  the  use  of  this 
invaluable  auxiliary  in  the  manipulation  of  crude  and  re¬ 
fined  oils,  by  reason  of  the  fact  that  no  pretentions  to  the 
possession  of  either  cpialification  can  be  entertained 
while  lacking  this  important  adjunct  to  efficient  oil  mill¬ 
ing. 

The  use  of  the  filter  press  renders  practicable  the 
transformation  of  the  crude  oil  into  a  marketable  product 
within  a  few  hours  subsequent  to  its  extraction  from  the 
crushed  seed,  a  circumstance  heretofore  impossible  of 
attainment,  owing  to  the  prolonged  period  requisite  for 
the  precipitation  of  the  foots  and  fine  vegetable  matter 
in  the  production  of  a  clarified  oil. 

The  separation  of  the  mealy  substance  from  the  oil 
is  effected  in  a  very  excellent  manner  by  the  use  of  the 
filter  press.  The  modus  opcrandi  consists  in  forcing  the 
fluid  through  the  press,  the  plates  of  which  are  covered 
with  textile  or  other  material,  permitting  the  oil  to  flow 
through  in  a  clarified  condition  while  retaining  the  foots. 
This  mealy  substance — in  oil  mill  parlance  recognized  as 
“foots” — slowly  accumulates  until  the  chambers  become 
clogged,  a  condition  which  makes  itself  apparent  by  the 
labored  efforts  of  the  jnimp,  and  the  consequent  in¬ 
crease  of  pressure  as  indicated  by  the  press  gauge.  The 
filtering  process  must  now  be  stopped  until  the  foots 
within  the  press  chambers  have  been  removed  and  the 
cloths  carefully  scraped,  where  such  are  in  use,  when  the 
plates  are  set  together  again  by  the  screw  and  the  regu¬ 
lar  work  resumed. 


THE  MANUFACTURE  OF  LINSEED  OIL. 


167 


By  securing  the  foots  in  this  concentrated  form — that 
of  caked  meal  impregnated  with  oil,  in  width  and  thick¬ 
ness  proportionate  to  the  filtering  area  of  the  chambers 
— a  great  saving  is  effected.  The  unpleasant  and  arduous 
duties  which  devolve  on  the  mill  hands  of  removing  the 
foots  from  the  bottom  of  storage  tanks  at  frequent  in¬ 
tervals  a.re  by  the  use  of  the  filter  press  wholly  obviated, 
d'he  characteristic  feature  of  tank  cleaning — that  of  a 
sloppy  and  greasy  condition  permeating  the  floor  and 
every  object  in  the  surrounding  vicinity,  together  with 
its  unavoidable  and  wasteful  concomitant,  a  greater  or 
less  loss  of  oil — are  now,  thanks  to  the  filter  press,  be¬ 
longing  to  the  past. 

A  pressure  exceeding  eighty  pounds  should  not  be 
maintained,  and  if  the  process  be  stopped  at  this  point, 
and  due  time  allowed  for  the  oil  in  the  chamber  to  run 
oft  prior  to  drawing  the  plates  apart,  it  will  be  found 
that  sufficient  meal  will  have  accumulated  to  form  a 
fairly-sized  cake.  By  placing  the  limit  of  pressure  at 
fifty  pounds  instead  of  eighty  pounds,  better  results  are 
obtainable. 

Any  good  pump  of  sufficient  capacity  to  supply  from 
100  to  300  gallons  per  hour  will  suffice,  but  if  fitted  with 
change  speed  or  of  the  duplex  variety,  the  filtering  pro¬ 
cess  is  maintained  more  uniformly,  the  latter  being  an 
indispensable  feature  in  the  production  of  a  perfectly 
filtered  oil.  The  first  form  of  pump  used  for  the  purpose 
was  fitted  with  a  relief  valve,  and  while  a  full  charge  of 
oil  was  continuously  delivered  to  the  filter  press,  the 
surplus  oil  was  permitted  to  flow  out  freely.  The  up¬ 
ward  movement  of  the  valve  caused  the  surplus  oil  to 
escape  and  return  to  the  suction  pipe.  A  spring  valve 
with  stuffing  box  on  the  adjusting  stem  and  placed  in  a 
I)ipe  connecting  the  suction  and  forcing  pipes  of  the 
pump  worked  satisfactorily.  By  setting  the  valve  to  the 


168 


THE  MANUFACTURE  OF  LINSEED  OIL. 


desired  pressure  it  was  constituted  a  sort  of  safety  valve, 
preventing  an  excessive  strain  on  the  press.  In  the  filter 
press  of  recent  construction  the  valve  is  sometimes  di¬ 
rectly  attached  thereto,  and  meets  the  requirements  of 
the  case  in  a  more  suitable  manner,  the  surplus  oil  fall¬ 
ing  to  the  expansive  pan  beneath,  and  by  gravity  slowly 
moving  to  the  suction  pipe. 

In  scraping  the  waxy  substance  from  the  surface  of  the 
filter  cloths  a  smooth-edged  plate  of  steel  should  be  used; 
or  hard  wood  champfered  to  suit,  in  size,  say,  about  three 
or  four  inches  long,  five  inches  wide  and  about  one-six¬ 
teenth  of  an  inch  thick.  In  the  case  of  the  steel,  the 
edges  must  not  be  sharp  or  the  textile  material,  where 
such  is  in  use,  will  be  cut.  In  the  event  of  paper  being 
used  as  the  filtering  medium,  and  the  increase  of  pres¬ 
sure  indicating  the  formation  of  a  cake  in  the  interior, 
the  outer  ply  of  the  eight  or  ten  which  may  be  in  opera¬ 
tion  is  removed,  the  foots  or  caked  substance  falling  to 
the  pan,  after  which  the  press  is  closed  and  the  operation 
resumed.  Recourse  is  made  to  this  simple  method  until 
the  number  of  sheets  of  filter  paper  has  been  reduced 
to  three  or  four,  when  a  fresh  lot  is  added. 

With  regard  to  the  cloths,  it  must  not  be  forgotten  that 
when  not  in  use  they  should  be  submerged  in  oil. 
Neglect  of  this  precautionary  measure  will  assuredly  ruin 
the  fabric,  more  especially  in  the  case  of  linseed  or  lard 
oil  filtration.  A  new  set  of  cloths  of  the  very  best  ma¬ 
terial  may  be  thus  irrecoverably  spoiled. 

In  the  event  of  the  press  being  required  to  remain 
idle  for  a  few  days,  a  simple  but  effective  method  of  keep¬ 
ing  the  cloths  moistened,  and  thereby  preserved,  without 
the  necessity  of  removing  them  from  the  plates  for  sub¬ 
mersion,  consists  in  charging  the  press  with  the  oil,  the 
outlets  being  shut.  This  is  impracticable,  however, 
where  shut-off  taps  are  not  fitted  to  the  plates;  but  the 


r 


THE  MANUFACTURE  OF  LINSEED  OIL. 


169 


liquid  may  be  slowly  pumped  through,  the  oil  con¬ 
tinuously  coursing  from  suction  tank  to  press,  and  re¬ 
turn.  By  repeating  this  operation  at  frequent  inter¬ 
vals,  the  material  is  preserved. 

When  through  omission,  or  from  any  other  cause,  fil¬ 
ter  cloths  used  in  the  clarification  of  linseed  oil  are 
permitted  to  dry  up  during  a  temporary  cessation  of  the 
filtering  operation,  the  damaging  effect  on  the  material 
is  more  serious  than  in  the  case  of  cottonseed  oil  filtra¬ 
tion.  The  drying  properties  of  linseed  oil  act  very  dele- 
teriously  on  the  surface  of  the  cloths  by  gumming  them, 
thus  blocking  the  minute  openings  between  the  woven 
!  threads,  rendering  them  impervious  to  the  oil,  and  con¬ 
sequently  valueless  as  a  filtering  medium. 

1  Cottonseed  oil,  which  possesses  drying  properties  to  a 
comparatively  trifling  extent,  is  not  so  injurious  to  the 
cloths  when  permitted  to  remain  thereon;  nevertheless, 
complete  submersion  guarantees  preservation  of  the  fab¬ 
ric  when  out  of  use  for  any  extended  period. 

The  cloth  used  in  the  filtration  of  lard  oil,  being  of 
'  the  same  texture,  requires  similar  attention  under  like 
circumstances.  The  coagulation  of  the  albuminous  de- 
posits  characteristic  of  animal  oils  displays  a  tendency 
to  clog  the  filtering  material  when  not  submerged  in  the 
liquid.  This  has  the  effect  of  damaging  them  equally 
with  that  of  the  gumming  tendency  of  linseed  oil  under 
similar  conditions. 

Impressed  with  the  fallacious  supposition  that  a  saving 
is  effecte^J  in  cost  of  filtering  material,  some  of  the  cot¬ 
tonseed  crushers  and  refiners  have  substituted  several 
plies  of  cotton-duck  cloth  on  each  plate  of  the  filter  press 
for  the  closely-woven  and  substantial  fabric  especially 
manufactured  for  that  purpose.  The  use  of  such  mate¬ 
rial  is  most  reprehensible,  and  viewed  from  a  practical 
and  economical  standpoint,  should  not  be  maintained 


170 


THE  MANUFACTURE  OF  LINSEED  OIL. 


under  any  condition  whatsoever.  To  obtain  an  oil  from 
which  the  ordinary  proportion  of  vegetable  matter  has 
been  eliminated,  as  is  the  case  where  a  suitable  filtering 
medium  is  utilized  by  means  of  such  flimsy  material  as 
the  common  fabric  referred  to,  becomes  a  practical  im¬ 
possibility.  The  tendency  of  the  duck  cloth  to  rend  at 
the  joints,  augments  the  difficulty  by  permitting  the  oil 
to  pass  out  unfiltered,  thus  materially  contributing  to  the 
defective  principle  involved;  that  is,  the  attainment  of 
perfect  filtration  by  inadequate  means. 

Not  infrequently  leaks  occur  by  reason  of  the  imprac¬ 
ticability  of  forming  permanently  tight  joints,  the  cheap 
material  separating  under  the  pressure  essential  to  form 
a  perfect  joint.  At  this  juncture  the  screw  is  set  up,  thus 
bringing  the  plates  closer,  the  object  being  to  stop  the 
leak  or  leaks-;  but  while  this  expedient  may  for  the  mo¬ 
ment  prove  effective,  aided  probably  by  the  dislodged 
foots  in  the  filter  chambers  forced  to  the  leaky  point  by 
the  escaping  fluid,  and  blocking  the  aperture  or  aper¬ 
tures  temporarily,  the  extra  pressure  exerted  at  the 
joints,  as  a  result  of  the  latest  movement  of  the  screw, 
will  eventually  manifest  itself  by  still  further  increasing 
the  undesirable  oil  exit,  until  perforce  the  operation  is 
brought  to  a  standstill.  The  press  is  then  permitted  to 
drain  off  its  fluid  contents,  the  fragmentary  cloth  or 
cloths  are  removed,  to  be  substituted  by  whole  material, 
which,  in  turn,  is  destined  to  be  similarly  cast  aside, 
probably  before  the  expiration  of  forty-eight  hours. 

The  use  of  filter  cloths  of  suitable  texture  is  much 
more  economical,  actually  costing  less  in  the  end,  with¬ 
out  reference  to  the  very  superior  product  obtained 
by  its  use  as  compared  with  that  of  the  frailer  material. 
Under  skillful  treatment  a  set  of  soiled  and  clogged  fil¬ 
ter  cloths  can  be  restored  to  their  original  usefulness,  or 
so  closely  approaching  it  that  the  difference  is  not  per- 


THE  MANUFACTURE  OF  LINSEEO  OIL. 


171 


ceptible;  and  this  may  be  successively  repeated  as  oc¬ 
casion  recjuires,  until  they  are  worn  out  by  prolonged 
usage.  Lack  of  adequate  knowledge  to  effect  a  thor¬ 
ough  cleansing  of  the  soiled  cloths  in  nine  cases  out  of 
ten  is  the  primary  cause  of  their  being  irrecoverably 
spoiled,  thus  precipitating  their  premature  abandonment. 

In  adjusting  the  cloths,  care  must  be  taken  that  they 
do  not  overlap,  for  the  reason  that  when  the  plates  are 
set  together  by  the  motion  of  the  screw,  an  imperfect 
joint  will  have  been  made,  a  circumstance  which  is  de¬ 
monstrated  the  moment  the  pump  is  put  in  motion  by  the 
rush  of  unfiltered  oil  from  the  defective  point.  Under 
these  circumstances,  the  pump  must  be  stopped  at  once, 
the  screw  relaxed,  and  after  the  press  is  drained,  the  dis¬ 
placed  fabric  is  restored  to  its  normal  position,  when  the 
work  can  be  resumed.  The  correct  management  of  the 
cloths,  in  adjusting  them  to  their  respective  positions,  is 
a  matter  of  considerable  importance.  By  overlapping, 
however  slightly,  an  exit  is  made  for  the  oil  through  the 
imperfect  joint  which  is  thereby  formed.  A  stream  so 
thin  that  its  presence  is  not  made  perceptible  may  flow 
for  hours  undetected.  This  has  the  effect  of  producing 
a  cloudy  oil,  and  in  a  proportionate  degree  rendering 
abortive  the  functions  which  the  filtering  apparatus  is 
expected  to  perform.  A  reliable  system  consists  in  view¬ 
ing  a  sample  of  the  oil  hourly  in  a  glass  test-tube  as  it 
flows  from  the  press.  Any  defect  in  the  operation,  not 
plainly  discernible,  is  thus  promptly  detected,  and  the 
usual  remedies  at  once  brought  into  requisition.  .If  the 
oil  is  bright  and  transparent,  the  work  is  progressing 
satisfactorily;  but  a  cloudy  condition  is  indicative  of  an 
irregularity  requiring  immediate  investigation. 

The  necessity  of  this  regular  examination  of  the  oil 
will  be  apparent  when  it  is  understood  that  not  infre¬ 
quently  a  leak  manifests  itself  when  least  expected,  al- 


172 


THE  MANUFACTURE  OF  LINSEED  OIL. 


though  the  filtering  medium  may  be  of  suitable  tex¬ 
ture  and  in  good  condition.  This  is  owing  to  the  yield¬ 
ing  or  stretching  of  the  cloths  at  the  joints,  thus  causing 
slight  leaks  by  slacking.  This  drawback  is  easily  reme¬ 
died  by  setting  up  the  screw,  pressing  the  plate  rims 
with  the  fabric  between  firmly  together,  and  thus  form- 
ing  tight  joints.  With  good  material  there  need  be  no 
apprehension  of  rending  the  cloths  by  thus  taking  up 
the  slack,  as  in  the  case  of  the  common  duck  cloth.  From 
the  time  a  new  set  of  cloths  are  first  put  into  operation, 
it  is  necessary,  at  proper  intervals,  to  take  up  this  re¬ 
laxation,  thus  lessening  the  risks  of  leaks. 

The  success  of  the  filtration  process,  together  with  the 
period  of  time  which  it  may  be  permanently  maintained, 
very  materially  depends  on  treatment  accorded  the  me¬ 
dium  used,  whether  felt,  paper,  or  woven  material.  Sev¬ 
eral  years  ago  the  writer  saw  a  valuable  filter  press  prac¬ 
tically  abandoned,  owing  to  insufficient  experience  in 
maintaining  the  cloths  in  proper  condition. 

A  set  of  good  cloths,  comprising  the  heavy  and  light 
variety  for  each  plate,  under  careful  management,  should 
give  satisfactory  results  for  six  months,  working  night 
and  day. 

There  are  various  forms  of  filter  presses  especially 
constructed  to  suit  the  respective  requirements  of  the 
industrial  arts.  The  original  form  of  press  was  fitted 
with  plates  of  circular  shape,  but  other  designs  have  been 
adopted,  and  are  now  in  general  use. 

The  concave  surface  of  the  circular  plates  forms  cham¬ 
bers  in  which  the  foots  are  retained.  The  press  of  later 
construction  consists  of  a  series  of  square  plates,  the 
chambers  being  formed  by  intermediate  frames,  and  the 
oil  inlet  differing  in  principle  as  well  as  in  design.  The 
plates  and  frames  rest  on  suitable  side-bars,  the  centre 
screw  forcing  the  head  block  plates  and  frames  together. 


THE  MANUFACTURE  OF  LINSEED  OIL. 


173 


As  previously  shown  in  the  case  of  the  circular-cham¬ 
bered  variety,  the  joints  are  made  by  the  filtering  me¬ 
dium,  which  is  adjusted  to  each  side  of  the  plates.  The 
plates  vary  in  size  from  eighteen  to  thirty-six  inches, 
while  for  such  material  as  ochre,  fuller’s  earth,  etc.,  a 
smaller  size  of  the  square-plate  kind  is  constructed. 

The  varnish  makers  of  Europe  and  America  realizing 
the  utility  of  the  filter  press,  have  very  generally 
adopted  it. 

In  the  form  of  press  used  for  the  production  of  paraf¬ 
fine  wax  and  other  materials  requiring  high  pressure, 
the  hydraulic  ram  is  used.  Wood  plate  presses  are  used 
for  filtering  substances  containing  acids,  the  iron  press, 
owing  to  the  corroding  action  of  the  latter,  being  un¬ 
available.  '  The  entrance  of  the  substance  to  be  filtered 
into  the  press  chambers,  varies  according  to  the  nature 
of  the  work  to  be  performed,  centre,  bottom,  corner,  and 
sometimes  upper  portion  of  the  plate  are  used,  the 
volume  filtered  varying  from  one  to  two  thou¬ 
sand  gallons,  according  to  size  of  the  press,  per 
twenty-four  hours.  During  this  period  they  must  be 
scraped  and  washed  as  occasion  requires.  After  three  or 
four  removals  of  the  caked  foots,  the  secondary  treatment 
of  washing  becomes  indispensable.  A  very  excellent 
patented  machine,  especially  constructed  to  facilitate  the 
cleansing  of  the  soiled  fabric,  has  been  on  the  market 
for  several  years,  its  use  proving  effective  and  economi¬ 
cal. 

The  practice  of  rapidly  pumping  the  fluid  through  the 
press  is  highly  deleterious.  A  slow  speed,  maintained 
under  uniform  pressure,  is  most  desirable,  and  other  con¬ 
ditions  being  normal,  satisfactory  results  are  obtainable 
in  every  instance.  A  force  pump  which  is  irregular  in  its 
motion  should  not  be  used.  Jerks  or  sudden  movements 
of  the  pump  plunger  rapidly  force  the  oil  through  the 


174 


THE  MANUFACTURE  OF  LINSEED  OIL. 


filtering  material,  the  proportion  thus  hurriedly  passed 
through  being  imperfectly  clarified.  A  steady  pushing 
motion,  characteristic  of  the  duplex  variety,  is  a  require¬ 
ment  of  perfect  filtration.  Pumps  are  specially  designed 
for  this  service,  and  efficient  work  will  be  best  subserved 
by  their  use. 

The  temperature  of  oil  intended  for  filtration  should 
not  exceed  70°  Fahrenheit.  This  temperature  is  obtained 
by  permitting  sufficient  time  to  elapse  subsequent  to  the 
extraction  of  the  oil,  during  which  period  the  precipita¬ 
tion  of  the  heavy  foots  is  effected  simultaneously. 

The  use  of  the  filter  press  materially  facilitates  sys¬ 
tematic  work  in  the  regular  manufacturing  processes, 
while  as  a  labor-saver  and  preventative  of  waste  and 
primarily  as  a  means  of  clarifying  a  newly  made  oil,  it  is 
incomparably  superior  to  old-time  principles. 

The  principle  involved  in  the  use  of  substantial  mate¬ 
rial  for  filtering  purposes  in  oil  mills,  has  equal  bearing 
on  the  various  industries  where  the  filter  press  is  oper¬ 
ated.  , 


BUCKEYE 

Iron  and  Brass  Works, 

DAYTON,  OHIO. 

Manufacturers  of 

f 

Linseed  and  Cotton¬ 
seed  Oil  Machinery. 

Engine  Builders. 

Steam  and  Water  Fitters. 

Brass  Goods  for  All  Purposes. 

WRITE  FOR  CATALOGUE. 


XII. 


WILLIAM  H.  SCHEEL, 

Importer 

Gums  and  Necessaries 

for  the  making  of 

Varnishes,  Lacquers,  Etc. 

172  Pearl  Street,  NEW  YORK,  N.  Y. 

THE  MANUFACTURE  OF  VARNISHES. 


MANUFACTURE  OF  OIL  VARNISHES, 

Oil  varnishes  are  divided  commercially  into  two 
groups,  coach  varnishes  and  cabinet  varnishes,  although 
there  is  very  little  difference  between  them  in  either  the 
method  of  making,  or  the  materials  from  which  they  are 
made.  The  former  are  the  best  and  most  durable  var¬ 
nishes  made,  the  best  materials  and  workmanship  being 
employed,  while  less  care  is  taken  with  cabinet  var¬ 
nishes.  The  process  of  manufacture  is,  however,  the 
same  for  all  the  oil  varnishes.  The  materials  used  are 
resins  of  various  kinds,  linseed  oil  (rarely  any  other  kind 
of  oil),  turpentine,  shale-petroleum,  or  resin-spirit,  and, 
for  some  special  sorts  of  varnish,  other  ingredients.  The 
process  usually  adopted  for  their  manufacture  will  be  first 
pointed  out;  then,  any  special  process  which  is,  or  has 
been  used;  then,  important  points  of  detail  in  the  pro¬ 
cess  will  be  noticed,  and  recipes  given  for  various  kinds 
of  oil  varnishes,  followed  by  a  section  dealing  with  their 
general  properties,  application,  etc. 

176 


THE  MANUFACTURE  OF  VARNISHES. 


177 


MANUFACTURE  OF  OIL  VARNISHES.— The 
method  and  plant  used  in  the  manufacture  of  this  class  of 
varnishes  are  comparatively  simple,  but  the  process  it¬ 
self,  while  being  so  simple,  is  one  that  requires  very 
great  care  and  experience  to  carry  out  to  a  successful 
end. 

The  process  in  outline  consists  of  the  following  stages: 

1st.  Melting  (or  “running”  as  it  is  known  in  the  trade) 
the  resin  or  “gum”;  2d,  boiling  the  oil;  3d,  mixing  the 
melted  gum  and  boiling  oil;  4th,  boiling  the  varnish; 
5th,  thinning  the  boiled  varnish;  6th,  clearing. 

1st.  “GUM  RUNNING.” — This*  is,  perhaps,  the  most 
delicate  operation  in  the  whole  process  of  varnish  mak¬ 
ing,  as  unless  it  is  well  done,  varnish  cannot  be  made,  no 
matter  how  well  the  rest  of  the  process  be  carried  out. 
“Running”  is  done  in  a  large  cylindrical  copper  vessel, 
the  “gum  pot;”  there  are  two  forms  of  this  gum  pot  in 
use;  one,  known  as  the  London  pot,  is  shaped  like  a  silk 
hat,  and  is  made  in  two  pieces,  viz.,  the  bottom 
formed  of  a  solid  piece  of  cast  copper  with  a  flange  cast 
on  it;  and  the  body,  which  is  a  cylinder  of  sheet  copper, 
riveted  to  the  bottom  piece.  There  is  a  very  consider¬ 
able  wear  of  the  bottom  part,  as  it  comes  in  contact  with 
the  fire,  and  hence  has  to  be  replaced  from  time  to  time; 
usually  a  bottom  will  last  about  three  months.  The  gum 
pot  usually  measures  about  26  inches  in  depth  by  10 
inches  in  diameter,  the  body  being  about  9  inches  deep. 
This  is  large  enough  to  run  about  8  pounds  of  gum  at 
one  time,  but  the  pots  are  often  made  large  enough  to 
hold  50  pounds  of  gum.  In  the  north  of  England  the 
gum  pot  is  made  of  a  different  shape,  from  which  it  will 
be  seen  that  it  differs  principally  in  the  shape  of  the  bot¬ 
tom,  which  is  made  conical.  The  main  advantage  of  this 
form  lies  in  the  fact  that  the  gum  runner  can  more  read¬ 
ily  ascertain  when  the  whole  of  the  gum  has  been  melted 


173 


THE  MANUFACTURE  OF  VARNISHES. 


by  probing  with  his  stirrer;  in. the  London  shape  parti¬ 
cles  of  unmelted  may  lodge  in  the  bottom  corners,  into 
which  it  is  difficult  to  work  the  stirrer,  whereas  in  North¬ 
ern  shape,  any  un melted  gum  must  settle  down  to  the 
point  of  the  conical  bottom,  and  its  presence  there  is 
easily  ascertained.  The  “gum  pot”  rests  by  flange  in  a 
suitable  hole  in  the  top  of  a  furnace.  In  modern  varnish 
works  the  top  of  the  furnace  forms  the  floor  of  the  gum¬ 
running  shed,  the  furnaces  themselves  being  fed  with  fuel 
from  the  outside.  The  pots  are  also  fitted  to  a  pair  of 
wheels,  by  which  they  can  be  wheeled  from  the  gum¬ 
running  shed  to  the  mixing  shed;  sometimes  rails  are 
laid,  on  which  the  pots  are  run.  As  a  very  considerable 
quantity  of  vapor  of  rather  an  acrid  character  is  given 
off  during  the  process  of  gum  running,  it  is  necessary  to 
lit  the  pots  with  a  hood  connected  with  a  flue,  by  which 
means  all  the  vapors  are  carried  into  a  chimney,  and  so 
away  out  into  the  atmosphere.  It  would  be  better,  how¬ 
ever,  to  take  the  vapors  into  a  large  condensing  cham¬ 
ber  to  allow  as  much  as  possible  of  them  to  condense 
into  a  liquid  form,  for  which  some  uses  (if  only  as  fuel 
for  the  furnaces)  could  be  found.  This  would  prevent  a 
considerable  amount  of  nuisance  being  generated  during 
the  process  of  varnish  making.  In  some  large  places 
where  they  have  steam  boilers,  the  vapor  is  carried  by 
means  of  a  pipe  to  the  ash-hole  of  the  fire-place,  and  thus 
passed  through  the  fire;  the  mouth  of  the  pipe  must  be 
covered  with  wire  gauze.  Prior  to  the  gum  being  run,  it 
is  broken  up  into  small  pieces  about  the  size  of  a  walnut. 
At  one  time  this  used  to  be  done  by  hand  with  a  ham¬ 
mer,  but  is  now  effected  by  a  machine  known  as  the 
breaker,  usually  consisting  of  a  pair  of  rollers  fitted  with 
teeth,  by  which  the  gum  is  broken  up  as  it  passes  be¬ 
tween  the  rollers. 


THE  MANUFACTURE  OF  VARNISHES. 


179 


2d.  OIL  BOILING. — While  the  gum  is  being  ‘'run” 
the  oil  to  be  used  is  boiled.  This  is  done  in  what  is 
known  as  the  boiling  pot,  which  is  the  same  in  shape  as 
the  oil  boiling  pots  described  when  dealing  with  the  boil¬ 
ing  of  linseed  oil.  The  oil  is  heated  to  about  500°  Fah¬ 
renheit  for  one  or  two  hours,  when  it  is  ready  for  mixing 
with  the  melted  gum.  The  boiling  of  the  oil  is  a  com¬ 
paratively  simple  operation,  and  there  should  be  no  dif¬ 
ficulty  in  carrying  it  out. 

8d,  MIXING. — When  the  gum  has  been  properly  run 
by  being  heated  in  the  gum  pot  until  it  is  in  a  cjuiet  state 
of  ebullition,  and  there  is  no  more  frothing;  which  al¬ 
ways  occurs  when  a  gum  is  first  heated,  and  which  is  a 
source  of  trouble  in  the  operation  of  gum  running  by 
causing  the  gum  to  boil  over  and  to  become  a  source  of 
danger  by  being  liable  to  take  fire  if  it  finds  its  way  into 
the  furnace,  as  well  as  being  a  loss  to  the  varnish  maker. 
This  frothing  is  probably  due  to  the  water  which  the 
resin  naturally  contains  being  driven  off,  as  well  as  to  the 
escape  of  the  more  volatile  constituents  of  the  resin; 
when  this  frothing  happens,  the  best  thing  to  be  done  is 
to  lift  the  pot  from  the  fire  and  beat  down  the  froth  as 
much  as  possible;  when  it  has  subsided,  the  pot  may  be 
replaced  on  the  fire,  and  the  gum  again  heated,  these 
proceedings  being  repeated  until  all  frothing  ceases. 
With  the  object  of  preventing  accidents  from  boiling 
over,  the  gum  pot  is  made  deep,  and  to  hold  a  much 
larger  quantity  of  gum  than  is  run  at  one  time. 

When  the  runner  considers  that  the  gum  has  been 
properly  melted  (on  which  point  experience  is  the  only 
reliable  guide),  the  necessary  quantity  of  boiling  oil  is 
taken  from  the  boiling  jjot  in  the  coi)per  jack  and  poured 
into  the  melted  gum,  which  is  stirred  energetically  all  the 
time.  When  properly  mixed,  the  contents  of  the  gum 
pot  are  poured  into  the  set  pot  (see  below) ;  the  gum  pot 


180 


THE  MANUFACTURE  OF  VARNISHES. 


is  then  ready  for  another  run  of  gum.  What  has  here 
been  described  is  called  a  “run;”  usually  a  large  number 
of  runs  are  made  and  put  into  the  set  pot  for  treatment 
at  one  time  by  the  next  operation. 

In  the  early  days  of  varnish  making  the  usual  quantity 
of  gum  run  at  one  time  was  8  pounds,  and  all  recipes 
for  making  varnish  are  based  on  this  figure;  but  nowa¬ 
days  quantities  of  50  or  GO  pounds  are  commonly  run  at 
one  time. 

4th,  BOILING. — For  the  purpose  of  boiling  the  mix¬ 
ture  of  oil  and  gum  so  as  to  cause  them  to  combine  to¬ 
gether  properly  and  to  increase  their  drying  properties, 
what  is  called  a  “set  pot”  is  used.  This  is  an  iron  ves¬ 
sel,  in  shape  resembling  a  washing  boiler,  having  a 
capacity  of  about  600  gallons,  and  set  in  a  suitably  con¬ 
structed  furnace.  Several  runs  of  gum  are  poured  into  it, 
and  the  whole  heated  or  boiled  at  from  450°  to  500° 
Fahrenheit.  The  duration  of  the  boil  varies  with  differ¬ 
ent  kinds  of  varnish,  and  may  range  from  half  an  hour  to 
4  or  5  hours.  When  sufficiently  boiled,  the  liquid  has  a 
certain  amount  of  stringiness.  When  the  gum  and  oil 
are  first  mixed  they  will  not  string,  that  is,  if  a  drop  be 
taken  between  the  finger  and  thumb,  and  these  be  ex¬ 
tended,  the  varnish  will  not  extend  in  the  form  of 
strings ;»  by  boiling,  it  obtains  this  property,  and  the 
longer  it  is  boiled  the  more  extensible  does  it  become; 
some  varnishes  only  require  a  moderate  amount  of 
stringiness;  others  require  a  great  deal;  instructions  on 
this  point  will  be  given  when  dealing  with  each  indi¬ 
vidual  varnish.  Another  effect  of  the  boiling  is  to  make 
the  varnish  clear  and  transparent;  the  mixture  of  gum 
and  oil,  when  first  made,  is  usually  rather  cloudy,  but 
clears  up  on  boiling. 

The  set  pot  should  be  so  placed  in  the  furnace  that  it 
can  be  readily  lifted  out  at  the  end  of  the  boiling,  and  be 


THE  MaNUEACTURE  of  VARNISHES. 


181 


taken  out  of  doors  away  from  the  proximity  of  the  fur¬ 
naces  for  the  next  operation.  As  a  further  precaution,  a 
shallow  concave  cover,  filled  with  sand,  should  be  slung 
by  chains  over  the  pot.  Should  the  oil  take  fire  during 
the  operation  of  boiling,  this  cover  is  quickly  lowered 
down  onto  the  pot,  and  the  fire  smothered  out  before  it 
has  taken  too  great  a  hold  of  the  oily  mass.  Water  is 
perfectly  useless  for  this  purpose,  and  should  never  be 
used  to  put  out  burning  oil;  there  is  nothing  better  for 
this  purpose  than  sand.  Varnish  making  is  always  sub¬ 
ject  to  the  danger  of  the  material  firing;  hence,  every 
precaution  should  be  taken  to  have  means  at  hand  to 
provide  the  promptest  extinction  of  the  flames.  It 
would  be  advisable  to  have  the  floor  of  the  running  and 
boiling  shops  made  of  sand,  so  that  if  any  oil  does  boil 
over  it  will  be  absorbed  by  the  sand  and  would  not  in¬ 
flame.  A  heap  of  sand  should  always  be  kept  in  a  con¬ 
venient  position,  so  that  it  may  be  thrown  on  any  oil 
that  may  by  chance  boil  over.  The  fireplace  should  be 
so  built  as  to  be  fed  from  the  outside. 

5th,  THINNING. — After  the  boiling  operation  de¬ 
scribed  above  is  completed,  the  set  pot  and  its  contents 
are  removed  from  the  fire  and  taken  out  of  doors,  if  the 
weather  permits,  or  into  a  shed  specially  used  for  this 
purpose,  and  which  is  at  some  distance  from  any  fire; 
here  it  is  mixed  with  turps,  to  thin  it  down  to  a  working 
consistency.  Turps  is  so  volatile  a  body  that  if  poured 
at  once  into  the  hot  varnish  mass  it  would  be  almost 
entirely  driven  off  as  a  vapor,  which  is  readily  inflam¬ 
mable  by  contact  with  a  fire  or  light.  This  thinning 
operation  should,  therefore,  always  be  done  at  some  con¬ 
siderable  distance  from  a  fire  or  light.  Turps  vapor,  be¬ 
ing  heavy,  travels  along  the  ground,  and  may  even  reach 
a  fire  20  feet  away.  Although  it  is  necessary  to  mix 
the  turps  with  the  varnish  mass  at  as  high  a  temperature 


18-2 


THE  MANUJ'ACTURE  OF  VARNISHES. 


as  possible,  yet  it  is  advisable  to  allow  the  hot  varnish 
mass  to  cool  down  somewhat  before  adding  the  turps;' 
this  should  also  be  added  in  small  quantities  at  a  time, 
and  each  lot  well  stirred  in  before  adding  the  next  lot; 
by  these  means  the  mixing  will  be  properly  done  without 
too  great  a  loss  of  turps. 

(ith,  CLEARING  AND  AGEING.— Freshly-made 
varnish  is  most  unsatisfactory  to  use,  and  all  the  best 
qualities  are  subjected  to  an  ageing  and  clearing  process 
before  they  are  sent  out.  This  process  consists  simply 
in  putting  them  into  large  iron  tanks  or  cisterns,  where 
the  varnish  is  kept  (free  from  exposure  to  the  atmos¬ 
phere)  for  periods  varying  from  six  months  to  one  and 
a  half  to  two  years.  During  this  time  the  particles  of  in¬ 
soluble  matter  fall  down,  and  the  constituents  becom¬ 
ing  more  thoroughly  amalgamated,  a  clearer,  more  trans¬ 
parent,  lustrous  and  more  easily  worked  varnish  is  ob¬ 
tained. 

Such  is  a  brief  description  of  the  usual  method  of  mak¬ 
ing  oil  varnishes.  The  quality  of  the  varnish  made  de¬ 
pends  upon  a  number  of  factors.  The  gum  must  be 
good  and  as  free  as  possible  from  particles  of  vegetable 
matter,  which,  in  the  running,  are  apt  to  char  and  thus 
discolor  the  resulting  varnish.  For  pale  varnishes,  clear, 
pale  gums  must  be  used;  and  the  running  must  be  both 
thorough  and  carefully  done,  since  there  is  no  remedy 
for  any  defect  due  to  a  bad  run;  while  one  such  run 
will  spoil  a  whole  batch  of  varnish.  It  should  always  be 
borne  in  mind  that  any  gum  left  unmelted  will  not  dis¬ 
solve  on  adding  the  oil.  Again,  the  temperature  of  run¬ 
ning  should  not  be  too  low  nor  too  high;  the  former  in¬ 
fluences  the  bloom  of  the  varnish,  while  the  latter  tends 
to  make  the  varnish  too  dark.  The  boiled  oil  should  be 
hot,  about  500°  to  550°  Fahrenheit,  so  that  on  being 
poured  into  the  melted  gum  it  will  mix  freely  and  not 


THE  Manufacture  of  varnishes. 


183 


cool  down  the  latter  too  much;  after  mixing  it  is  advis¬ 
able  to  boil  the  mixture  for  about  ten  minutes  before 
pouring  it  out  into  the  set  pot.  The  best  practical  guide 
to  all  these  and  other  points  in  varnish  making  is  experi¬ 
ence.  The  linseed  oil  used  should  be  of  the  very  best 
quality,  as  good. varnish  cannot  be  made  from  poor  oil, 
and  it  ought  to  be  kept  in  covered  tanks  for  some  months 
before  using.  The  turps  should  also  be  of  good  quality; 
it  is  improved  by  keeping. 

Another  method  of  making  varnishes,  which  was  much 
advocated  by  Tingry,  is  to  melt  the  gum  in  the  usual 
way;  then  to  run  it  out  on  to  a  cold  surface,  so  that  it 
would  solidify  in  sheets;  when  cold,  the  solid  gum  is 
roughly  powdered,  put  into  the  boiling  pot  with  the  oil 
and  boiled  up  as  described  above.  In  mixing,  3  pounds 
of  melted  gum  should  be  reckoned  as  equal  to  4  pounds; 
in  other  respects,  the  same  quantities  of  oil,  etc.,  may  be 
taken.  The  varnishes  made  by  this  method  cannot  be 
distinguished  from  those  made  by  the  old  method. 
Tingry  advised  keeping  the  gum  melted  until  it  had  lost 
25  per  cent  of  its  weight,  and  he  devised  a  special  form  of 
melting  apparatus  by  which  this  could  be  done;  but  the 
process  was  (for  several  reasons)  a  rather  unpractical 
one. 

It  is  stated  in  many  accounts  of  varnish  making  that 
oil  varnishes  may  be  made  by  boiling  the  gum  in  oil.  As 
a  general  rule,  this  is  not  correct.  A  few  gums  may  be 
dissolved  in  this  way,  but  most  of  the  oil  varnish  gums 
obstinately  refuse  to  be  transformed  into  varnishes  by 
this  method. 

RECIPES. — Oil  varnishes  are  divided  by  the  trade 
into  coach  varnishes  and  cabinet  varnishes;  but  there  is 
no  essential  difference  between  them;  they  are  made  in 
the  same  way  and  often  from  the  same  materials;  the  dif¬ 
ference  is  due  to  the  carriage  varnishes  being  made  from 


184 


THE  MANUFACTURE  OF  VARNISHES. 


better  qualities  of  gums  and  oil  and  a  little  more  care 
being  taken  in  their  preparation.  The  following  recipes 
are  taken  from  the  most  reliable  sources  and  give  par¬ 
ticulars  for  preparing  all  the  varieties  of  oil  varnishes 
now  in  use.  The  preparation  of  varnishes  is  considered 
a  trade  secret;  and  it  is  difficult  to  obtain  reliable  infor¬ 
mation  on  the  subject.  What  is  here  given  and  what  is 
to  be  found  in  most  accounts  is  based  on  a  lecture  on 
varnish  making  given  by  Mr.  J.  Wilson  Neil  to  the  So¬ 
ciety  of  Arts  many  years  ago,  and  published  in  an  early 
volume  of  their  Transactions,  which  is  difficult  to  obtain 
now. 

The  proportions  are  generally  given  as  for  a  run  of  8 
pounds  of  gum. 

1.  FINISHING  BODY  VARNISH  FOR 
COACHES. — Run  8  pounds  of  the  best  African  animi, 
pour  in  2  gallons  of  the  best  oil  well  boiled,  set  very 
slowly  (by  boiling  4  to  5  hours  until  it  strings  well),  al¬ 
low  to  cool  and  add  3^  gallons  of  turps;  strain  and  allow 
to  age.  This  varnish  is  considered  to  be  the  best  varnish 
made,  but  it  requires  considerable  care  in  making  it  to 
obtain  it  of  good  quality;  the  best  and  palest  gum  and 
the  best  oil  must  be  used. 

2.  HARD  DRYING  OR  FLATTING  VARNISH. 
— This  is  made  by  running  8  pounds  of  gum  animi,  mix¬ 
ing  with  2  gallons  of  oil,  and,  after  boiling  for  4  hours, 
thinning  with  3^  gallons  of  turps. 

This  varnish  dries  rather  harder  than  the  above  and 
quicker — i.  e.,  in  about  8  to  10  hours.  It  is  , chiefly  used 
for  the  under  coats  of  varnish  on  a  coach  body. 

This  varnish  is  used  for  the  surface  coats  of  carriages, 
is  pale  in  color,  and  dries  with  a  brilliant  surface  in  about 
12  hours.  It  is  a  very  durable  varnish,  and  will  resist  the 
destructive  action  of  the  atmosphere  very  well. 


THE  MANUFACTURE  OF  VARNISHES. 


185 


3.  ELASTIC  CARRIAGE  VARNISH  (1).— Run  8 
pounds  of  good  quality  gum  copal,  mix  with  2^  gallons 
of  oil,  add  |  pound  of  dried  copperas  and  ^  pound  of 
litharge,  boil  until  it  strings,  then  allow  to  cool  and  thin 
with  5^  gallons  of  turps.  Run  8  pounds  of  second  sort 
gum  animi,  mix  with  2-|  gallons  of  oil,  add  ^  pound  dried 
sugar  of  lead  and  ^  pound  of  litharge,  boil  until  it  strings, 
allow  to  cool  and  thin  with  gallons  of  turps.  The  two 
lots  are  mixed  together,  strained,  and  allowed  to  mature. 
This  varnish  dries  hard  with  a  fine  polish  in  about  5 
hours  in  summer  and  in  about  7  hours  in  winter.  It  is 
used  for  varnishing  common  carriages,  and  also  for  cabi¬ 
net  work. 

4.  ELASTIC  CARRIAGE  VARNISH  (2).— Run  8 
pounds  of  first  quality  gum  copal,  mix  with  3  gallons  of 
oil,  boil  for  4  hours  until  it  strings,  then,  after  cooling, 
add  gallons  of  turps.  Run  8  pounds  of  best  gum 
animi,  mix  with  2  gallons  of  oil,  and,  after  boiling  until 
it  strings,  thin  with  3|  gallons  of  turps.  Two  pots  of 
this  running  are  mixed  with  one  pot  of  the  first  running, 
and  the  whole  is  strained  and  allowed  to  mature.  This 
varnish  is  much  used  as  the  finishing  varnish  for  com¬ 
mon  coaches,  and  for  the  under  parts  of  superior  coaches. 
It  dries  brilliant  and  is  durable.  It  is  rather  quicker  in 
drying  than  No.  1,  taking  about  10  hours  in  summer  and 
12  hours  in  winter. 

5.  ELASTIC  CARRIAGE  VARNISH  (3).— Run  8 
pounds  of  gum  copal,  mix  with  2  gallons  of  oil,  boil  until 
it  strings,  then  thin  with  3^  gallons  of  turps.  Run  8 
pounds  of  gum  animi,  mix  with  2  gallons  of  oil,  boil  as 
before,  and  thin  with  3|  gallons  of  turps.  Mix  one  pot 
of  this  running  with  one  pot  of  the  previous  running, 
strain,  and  finish  in  the  usual  way.  As  good  a  quality 
of  gums  is  not  used  in  making  this  varnish  as  the  last,  so 


186 


THE  MANUFACTURE  OF  VARNISHES. 


that  it  is  usually  rather  darker,  although  it  is  quite  dur¬ 
able.  It  dries  in  about  the  same  time. 

6.  ELASTIC  HARD  CARRIAGE  VARNISH.— 
Run  8  pounds  of  gum  copal,  mix  with  2  gallons  of  oil, 
add  I  pound  of  dried  sugar  of  lead,  and  boil  until  stringy; 
thin  with  3^  gallons  of  turps.  Run  8  pounds  of  gum 
animi,  mix  with  2  gallons  of  oil,  add  ^  pound  of  dried 
copperas,  and  boil  until  it  strings;  thin  with  3^  gallons  of 
turps.  Both  runnings  are  mixed  together  and  finished 
in  the  usual  way.  This  varnish  is  used  for  the  under 
coats  in  varnishing  carriages;  it  dries  hard  in  about  5 
to  6  hours,  and  gives  a  smooth  surface. 

7.  CARRIAGE  VARNISH. — Run  8  pounds  of  sec¬ 
ond  quality  gum  animi,  mix  with  2|  gallons  of  oil,  add 
I  pound  each  of  litharge,  dried  copperas,  and  dried  sugar 
of  lead,  boil  until  it  strings;  then  thin  with  5^  gallons  of 
turps,  and  finish  in  the  usual  way.  This  varnish  is  used 
for  varnishing  dark-colored  carriages,  the  iron-work  of 
coaches,  and  for  ordinary  cabinet  work.  It  dries 
quickly  in  about  4  hours  in  summer  and  5  hours  in  win¬ 
ter,  with  a  hard  and  glossy  surface.  It  is  not  so  durable 
as  the  other  varnishes  described  above, 

8.  PALE  OAK  VARNISH. — Eight  pounds  of  gum 
copal  are  run  and  mixed  with  3  gallons  of  oil;  |  pound 
each  of  dried  copperas,  dried  sugar  of  lead,  and  litharge 
are  added;  the  mixture  well  boiled  and  thinned  with  5^ 
gallons  of  turps,  and  the  varnish  strained  and  finished 
in  the  usual  way.  This  varnish  is  used  for  all  kinds  of 
best  cabinet  varnish;  it  dries  in  about  4  hours  with  a 
hard  and  durable  surface. 

9.  OAK  VARNISH. — Made  in  the  same  way  as  the 
last,  but  from  a  poorer  quality  of  gums. 

10.  HARD  CHURCH  OAK  VARNISH.— Run  8 
pounds  of  gum  kauri;  mix  with  3  gallons  of  oil;  boil  until 
it  strings  well;  then,  after  cooling,  thin  with  gallons 


THE  MANUFACTURE  OF  VARNISHES. 


187 


•  of  turps.  This  varnish  dries  with  a  hard,  glossy  surface 

I  in  from  6  to  7  hours.  It  is  not  a  durable  varnish  if  used 

;  in  positions  where  it  is  exposed  to  the  weather,  but  for 

all  interior  work  it  stands  well,  and  resists  a  great  deal 
of  wear  and  tear. 

11.  No.  2  HARD  CHURCH  OAK  VARNISH.— 
This  is  made  in  the  same  way  as  the  last;  only  poorer 
qualities  of  gums  are  used. 

12.  PALE  COPAL  VARNISH.— Carefully  select  8 
pounds  of  the  palest  gum  copal;  run  well,  and  mix  with 
2  gallons  of  pale  boiled  oil ;  boil  the  whole  until  it  strings, 
then  allow  to  cool  down  a  little,  and  thin  with  5^  gallons 
of  turps.  Strain  and  finish  as  usual.  When  well  made 
this  varnish  is  very  pale,  and  dries  with  a  lustrous,  dur¬ 
able  coat,  in  from  8  to  10  hours. 

13.  JAPANNERS’  GOLD  SIZE. — Run  10  pounds  of 
gum  animi  and  mix  it  with  2  gallons  of  hot  oil;  prepare 
two  runs  of  this.  In  the  set  pot  place  10  gallons  of  oil 
and  boil  it  well  for  2  hours;  then  add  7  pounds  of  red 
lead,  7  pounds  of  litharge,  and  3  pounds  of  copperas; 
the  addition  of  these  driers  is  best  made  in  small  quan¬ 
tities  at  a  time,  the  whole  mass  being  kept  boiling  all  the 
time;  when  all  the  driers  have  been  added,  the  boiling 
should  be  continued  for  about  3  hours  longer.  Some¬ 
times  the  addition  of  the  driers  causes  the  boiling  oil  to 
froth  up  very  much ;  in  such  cases  it  is  best  to  reduce  the 
fire  somewhat,  and  to  take  some  of  the  oil  out  of  the  pot, 
adding  it  again  as  the  frothing  subsides.  When  the  oil 
has  been  boiled  for  3  hours  the  two  runs  of  gum  are 

j  added,  and  the  boiling  is  continued  for  5  hours,  when  it 

?  will  begin  to  string;  the  boiling  is  continued  until  the 

I  mass  drops  off  the  ladle  or  stirring  rod  in  large  drops, 

I  and  strings  well.  Then  allow  to  cool,  which  will  take 

1  about  2  hours;  pour  in,  in  small  quantities  at  a  time,  30 

I  gallons  of  turps;  as  this  is  being  poured  in  the  whole 

* 


188 


THE  MANUFACTURE  OF  VARNISHES. 


mass  must  be  thoroughly  stirred  up,  so  as  to  get  the 
turps  and  varnish  well  mixed;  the  mixing  with  the  turps 
must  not  be  done  too  quickly,  or  otherwise  there  is  too 
great  a  liability  to  boil  over;  in  fact,  this  applies  to  the 
rnixing  of  turps  in  making  all  these  oil  varnishes.  This 
gold  size  will  dry  in  about  10  minutes,  if  well  made;  al¬ 
though  sometimes  it  may  take  25  minutes  to  dry. 

14.  BLACK  JAPAN  (1). — This  is  made  in  a  very 
similar  manner  to  the  gold  size  just  described.  Into  the 
set  pot  put  6  gallons  of  linseed  oil,  boil  it  on  a  slow  fire 
for  2  hours,  then  run  in  a  gum  pot  10  pounds  of  asphal- 
tum,  and  mix  with  2  gallons  of  oil ;  when  mixed,  pour 
into  the  set  pot;  then  run  three  more  lots,  pouring  each 
one  as  it  is  run  into  the  set  pot;  then  add  7  pounds  of  red 
lead,  7  pounds  of  litharge,  and  3  pounds  of  copperas,  in 
small  quantities  at  a  time;  keep  the  mixture  boiling 
slowly  for  4  hours  longer;  then  allow. to  stand  till  the 
next  day,  when  it  is  boiled  until  a  small  quantity  taken 
out  on  a  glass  will,  when  rubbed  or  rolled  in  the  fingers, 
set  hard;  it  is  now  allowed  to  cool,  and  when  sufficiently 
cold,  30  gallons  of  turps  are  added.  If  after  the  japan 
has  become  cold  it  is  found  to  be  too  stiff,  then  it*  can  be 
warmed  up  and  more  turps  added  until  it  attains  the 
right  consistency.  This  japan  is  used  for  all  kinds  of 
ironwork  about  carriages  which  are  to  be  black;  it  dries 
with  a  hard,  durable,  lustrous  coat  in  about  8  hours. 

15.  BLACK  JAPAN  (2). — A  better  quality  of  black 
japan  which  will  dry  harder  and  more  glossy,  is  made  as 
follows:  Melt  48  pounds  of  asphaltum  in  the  set  pot, 
and,  when  melted,  add  10  gallons  of  oil;  run  in  the  gum 
pot  8  pounds  of  common  gum  animi,  and  mix  with  it  2 
gallons  of  oil;  pour  the  mixture  into  the  set  pot;  then 
run  10  pounds  of  common  amber,  and  mi.x  with  2  gal¬ 
lons  of  oil;  this  running  is  also  added  to  the  set  pot,  the 
.contents  of  which  are  boiled  for  3  hours  longer,  during 


THE  MANUFACTURE  OF  VARNISHES. 


189 


which  time  7  pounds  of  red  lead,  7  pounds  of  litharge, 
and  3  pounds  of  copperas  are  added,  and  the  boiling 
continued  until  the  mass  sets  between  the  fingers  into  a 
hard  mass.  Allow  it  to  cool;  then  thin  with  30  gallons 
of  turps,  as  before. 

16.  BLACK  VARNISH  FOR  CARRIAGE  IRON¬ 
WORK. — Run  48  pounds  of  asphaltum  in  the  set  pot 
and  add  10  gallons  of  boiled  oil,  7  pounds  of  red  lead,  7 
pounds  of  litharge,  and  3  pounds  of  copperas;  run  8 
pounds  of  copal,  mix  with  2  gallons  of  oil,  and  add  to  the 
set  pot;  boil  the  whole  for  4  hours;  place  on  one  side 
till  the  next  day,  and  then  boil  until  it  sets  hard  between 
the  fingers;  then,  after  cooling,  thin  with  30  gallons  of 
turps.  This  dries  hard,  with  a  good  surface,  in  about  3 
hours. 

17.  BRUNSWICK  BLACK  (1).— This  very  useful 
black  varnish  is  made  in  several  ways.  Run  45  pounds 
of  asphaltum  for  6  hours  in  a  set  pot.  Boil  6  gallons  of 
oil  with  6  pounds  of  litharge  until  it  strings  well;  pour 
into  the  set  pot  with  the  asphaltum,  and  boil  the  whole 
until  it  will  set  hard  between  the  fingers;  then  allow  to 
cool,  and  thin  with  25  gallons  of  turps.  This  dries  in 
about  4  hours,  with  a  good  surface,  having  a  brilliant 
gloss. 

18.  BRUNSWICK  BLACK  (2).-^  A  commoner 
Brunswick  black  is  made  as  follows:  Twenty-eight 
pounds  of  coal-tar  pitch  and  28  pounds  of  asphaltum  are 
boiled  together  in  the  set  pot  for  6  hours;  the  mixture  is 
allowed  to  stand  all  night,  after  which  it  is  boiled  up  and 
8  gallons  of  boiled  oil  are  added;  10  pounds  of  litharge 
and  10  pounds  of  red  lead  are  added,  in  small  quantities 
at  a  time,  and  the  mass  boiled  until  it  will  set  hard  be¬ 
tween  the  fingers;  it  is  then  allowed  to  cool,  and  is  mixed 
with  20  gallons  of  turps.  This  will  dry  in  about  1  to  2 


190 


THE  MANUFACTURE  OF  VARNISHES. 


hours,  and  is  a  good  black  varnish  for  all  kinds  of  iron¬ 
work. 

19.  BLACK  LEATHER  VARNISH.— A  very  good 
black  varnish  is  made  by  boiling  10  pounds  of  linseed 
oil  with  4  pounds  of  litharge  for  about  5  hours,  and  then 
coloring  with  lamp-black.  Other  leather  varnishes  will 
be  found  described  under  spirit  varnishes. 

20.  AMBER  VARNISH. — Run  6  pounds  of  the 
palest  amber,  mix  with  2  gallons  of  oil,  and  boil  until 
it  strings;  then  thin  with  3^  gallons  of  turps.  This  forms 
one  of  the  most  durable  varnishes  known;  it  is  much 
used  for  varnishing  pictures. 

21.  COPAL  PICTURE  VARNISH.— Run  8  pounds 
of  the  very  best  and  palest  copal,  mix  with  3  gallons  of 
oil,  and  boil  until  it  strings  well;  then  thin  with  3  gallons 
of  turps.  When  good  materials  are  used,  a  pale,  durable 
varnish  is  obtained. 

22.  OIL  VARNISH. — Boil  6  gallons  of  linseed  oil 
with  1  pound  of  sugar  of  lead  for  5  hours.  Other  driers 
may  be  used  instead  of  the  sugar  of  lead,  such  as  sulphate 
of  zinc,  borate  of  lead,  and  borate  of  manganese.  Only 
a  very  small  quantity  of  the  last  is  required,  or  about  1 
pound  to  70  or  80  gallons  of  oil. 

23.  GOLD  SIZE. — Run  8  pounds  of  gum  copal,  mix 
with  2  gallons  of  oil,  boil  until  it  begins  i-o  string,  then 
add  ()  gallons  o.f  boiling  oil,  and  thin  with  turps  to  the 
required  consistency.  This  does  not  dry  as  (juickly  as 
japanners’  gold  size,  and,  as  its  name  indicates,  is  used 
for  fastening  gold  leaf  to  glass  and  other  objects. 

GENERAL  CONSIDERATIONS.— The  following 
general  features  concerning  oil  varnishes  and  their 
manufacture  should  be  noted.  An  oil  varnish  should 
possess  the  following  properties:  1st,  good  and  free 
working;  2d,  drying  hard  and  rulibing  freely;  3d,  giv¬ 
ing  an  elastic  coating  not  liable  to  crack  or  bloom,  and 


THE  MANUFACTURE  OF  VARNISHES. 


191 


which  is  resistant  to  the  destructive  action  of  the  atmos¬ 
phere.  It  is  difficult  always  to  secure  these  features  of  a 
good  varnish  especially  to  combine  the  second  and  third, 
as  hardness  and  elasticity  are  somewhat  opposed  to  one 
another. 

In  the  preparation  of  these  varnishes  too  much  care 
cannot  be  exercised  in  carrying  out  the  various  opera¬ 
tions.  The  materials  should  be  carefully  selected;  good 
varnish  cannot  be  made  from  a  poor  quality  of  gum, 
and,  no  matter  how  good  this  may  be,  the  use  of  a  bad 
sample  of  oil  will  spoil  any  varnish  made  from  it;  the 
quality  of  the  turpentine  used  also  has  some  influence. 
In  the  sections  referring  to  these  materials  will  be  found 
information  as  to  the  qualities  required  in  good  materials. 
The  better  the  gum  or  resin  is  run,  the  larger  will  be  the 
quantity  of  varnish  obtained,  and  this  will  be  stronger 
and  better  for  working.  The  boiling  of  the  oil  and  resin 
together  must  be  well  done;  if  not  sufficiently  boiled,  the 
resulting  varnish  does  not  work  freely,  and  is  sometimes 
liable  to  bloom.  This  latter  defect  also  occurs  in  var¬ 
nishes  made  from  badly-run  gums.  The  stringing  or 
boiling  should  be  done  slowly,  and  at  as  low  a  heat  as 
possible;  if  brought  forward  too  quickly  by  the  use  of 
too  much  heat,  then  the  resulting  varnish  is  liable  to  be 
discolored.  It  takes  more  turps  to  thin  it  down,  and  the 
varnish  neither  works  so  freely  under  the  brush,  nor 
gives  such  a  smooth,  brilliant  surface  as  a  good  oil  var¬ 
nish  should  do.  The  more  oil  there  is  used  in  the  com¬ 
position  of  a  varnish,  the  more  elastic  and  less  liable  to 
crack  is  the  coat  formed  by  the  varnish.  On  the  other 
hand,  the  drying  is  retarded  by  using  too  little  oil.  The 
more  gum  there  is  put  into  a  varnish,  the  thicker,  firmer, 
more  quickly  drying,  and  more  brilliant  when  dry,  is  the 
coat  formed;  on  the  other  hand,  it  is  more  liable  to  crack 
if  there  is  too  little  gum.  The  varnishes  made  by  the 


192 


THE  MANUFACTURE  OF  VARNISHES. 


French  method  (which  contain  little  oil)  are  rather  liable 
to  these  defects  of  cracking  because  of  the  want  of  elas¬ 
ticity  in  the  coat  they  form. 

Driers,  especially  copperas,  when  added  to  varnishes 
have  a  tendency  to  make  the  varnishes  opaque,  and  to 
harden  them.  An  oil  varnish  made  with  quick  driers 
forms  a  coat  which  is  hard,  non-elastic,  liable  to  crack 
and  of  short  duration. 

The  usual  proportions  of  resins  are, for  body  varnishes, 
about  to  pounds  per  gallon;  for  carriage  and  cabi¬ 
net  varnishes,  from  1  to  Ij  pounds  per  gallon;  for  gold 
size  and  japans,  from  ^  to  f  pound  per  gallon.  If,  after 
making  and  cooling,  the  varnishes  are  found  to  be  too 
thick,  they  can  be  reduced  to  the  required  consistency  by 
warming  (so  as  to  render  them  more  fluid)  and  adding 
turps. 

Varnishes  should  be  kept  at  least  six  months  after 
making  before  they  are  used;  this  ageing  causes  a  bet¬ 
ter  amalgamation  of  the  constituents  of  the  varnish,  in¬ 
creases  the  ease  with  which  it  works  under  the  brush, 
and  causes  it  to  form  a  smoother  and  more  lustrous  coat. 

Lacquers  and  Varnishes. 

MANUFACTURE  OF  FAT  COPAL  VAR- 
NISFIES. — Violette,  who  has  thoroughly  studied  the  ac¬ 
tion  of  copal  subjected  to  high  temperatures,  and  its  solu¬ 
bility,  recommends  the  following  process  for  the  manu¬ 
facture  of  copal  varnish :  The  copal  is  first  heated  to  680° 
Fahrenheit  until  it  has  lost  20  to  25  per  cent  of  its  weight, 
when  a  suitable  mixture  of  linseed  oil  and  oil  of  turpen¬ 
tine  is  dissolved  in  the  melted  copal  at  212°  Fahrenheit. 

The  melting  and  distillation  of  copal  is  an  operation 
which,  as  a  definite  temperature  must  be  kept  up,  is  very 
difficult  to  execute  on  a  large  scale.  The  following  ap¬ 
paratuses  have  been  tested  and  approved  by  Violette. 


THE  MANUFACTURE  OF  VARNISHES. 


193 


The  arrangement  consists  of  a  clay  crucible  about  8 
inches  in  diameter  and  12  inches  deep,  resting  in  a  fur¬ 
nace.  The  crucible  is  heated  to  such  a  degree  that  zinc 
will  just  melt  in  it.  The  balloon  is  then  brought  into  the 
crucible.  It  contains  f  pound  of  copal  and  is  suspended 
from  a  balance,  the  right  scale  pan  of  which  contains 
the  tare  of  the  balloon  and  the  copal,  while  upon  the  left 
scale  pan  is  placed  a  quarter  of  the  weight  of  the  copal. 
The  vapors  from  the  copal  escape  through  the  opening  in 
the  chimney.  When  25  per  cent  of  the  copal  has  been 
distilled  off,  the  beam  of  the  balance  assumes  a  horizon¬ 
tal  position,  and  the  balloon  is  lifted  from  the  crucible, 
the  distillation  being  finished.  The  melted  copal  is  dis¬ 
tributed  on  the  sides  of  the  balloon  by  swinging  the  lat¬ 
ter,  when  it  is  allowed  to  cool  off  somewhat,  and  then  1 
pint  of  oil  of  turpentine  and  5  ounces  of  linseed  oil  are 
added. 

A  cast-iron  block  weighing  about  300  pounds,  which 
can  be  easily  kept  at  a  definite  temperature,  is  used. 

It  is  heated  to  750°  Fahrenheit,  and  then  a  little  box 
containing  If  ounces  of  copal,  is  placed  in  the  hollow 
space. 

A  moderate  fire  is  kept  up  to  prevent  the  block  from 
becoming  cool.  The  vapors  evolved  from  the  copal 
escape  from  the  space  closed  with  the  cover  through  a 
pipe,  are  condensed  by  the  cooling  apparatus,  and  col¬ 
lected  as  a  yellow,  clear  fluid  in  a  conveniently  situated 
vessel.  The  operation  is  interrupted  as  soon  as  a  quan¬ 
tity  corresponding  to  the  fourth  part  of  the  copal  has 
been  collected,  when  the  box  is  taken  from  the  cavity  in 
the  block  and  the  copal  poured  out. 

Another  modification  of  the  distilling  apparatus  is 
represented  by  a  copper  sphere,  silvered  inside,  and  hav¬ 
ing  a  diameter  about  20  inches,  which  can  be  turned  by 
means  of  a  handwheel  around  a  horizontal  shaft.  After 


194 


THE  MANUFACTURE  OF  VARNISHES. 


10  pounds  of  copal  have  been  placed  in  the  globe  and  the 
opening  closed,  a  moderate  fire  is  started  and  the  globe 
slowly  turned. 

Varnish  prepared  in  this  manner  is  soluble  in  ether. 
Violette  recommends  the  following  proportions  for 
copal:  One  pound  of  copal  and  2  pounds  of  sulphuric 
ether.  The  resin  is  powdered,  placed  in  the  flask,  and  the 
ether  gradually  added  with  vigorous  shaking,  and  the 
flask  hermetically  closed.  Solution  takes  place  readily. 
The  varnish  thus  prepared  is  cleared  by  allowing  it  to 
stand,  and  before  using  it,  filtered  through  paper  or  linen. 

SPIRIT  LACQUERS  are  especially  adapted  for 
polishing  fine  woods  and  coating  maps,  book-covers,  etc. 
The  only  objectionable  point  in  using  them  for  metal  is 
that  they  do  not  adhere  tightly.  This  can  be  remedied 
by  using  crystallized  boracic  acid,  ^  part  of  which  is  dis¬ 
solved  in  1,000  parts  of  the  respective  lacquer.  When 
this  is  applied  to  a  bright  metal  surface  it  forms  a  hard, 
glassy  coating  which  cannot  be  scratched  off  with  the 
finger-nail. 

IRON  LACQUERS  are  all  prepared  in  a  very  simple 
manner  by  melting  pitch  with  various  products  of  the  dis¬ 
tillation  of  tar.  The  pitch  is  melted,  with  an  addition  of 
the  oil,  in  an  open  iron  boiler  heated  from  the  outside. 
The  oil  accelerates  the  melting  of  the  pitch  and  prevents 
it  from  congealing  too  rapidly. 

After  the  pitch  has  become  liquid  it  is  advisable  to  al¬ 
low  it  to  cool  somewhat  before  adding  the  oil,  to  prevent 
the  latter  from  boiling.  Add  the  oil  gradually,  and  stir 
each  portion  thoroughly  into  the  pitch  before  adding 
the  next.  To  see  whether  the  varnish  has  the  right  con¬ 
sistency  take  occasionally  a  sample  from  the  boiler,  al¬ 
lowing  it  to  cool.  An  exact  statement  as  to  the  quantity 
of  oil  to  be  used  cannot  be  given,  since  the  consistency  of 


tHE  MANUEacTUrE  of  VaRNISHES. 


195 


the  varnish  depends  on  the  purpose  for  which  it  is  to  be 
used,  and  the  demands  of  the  consumer. 

CLARIFYING  VARNISH.— A  method  of  clarifying 
varnishes  and  other  liquids  and  removing  impurities  in 
48  hours  is  as  follows:  Mix  with  every  10  gallons  of  var¬ 
nish  8  ounces  each  of  powdered  marble-dust  and  burnt 
oyster-shells.  All  the  impurities  in  the  varnish  will  be 
attracted  by  and  adhere  to  the  oyster-shell  dust,  and  the 
weight  of  the  marble-dust  mixed  therewith  precipitates 
every  floating  particle  to  the  bottom  of  the  vessel  con¬ 
taining  the  varnish.  This  process  may  also  be  applied  to 
the  clarification  of  turpentine,  oils  and  molasses. 

FILTERING  VARNISHES.— The  apparatus  pre¬ 
vents  a  loss  of  solvent,  as  spirit  of  wine,  benzole,  etc.,  by 
evaporation.  It  consists  of  a  large  flask,  either  of  glass 
or  tin,  closed  by  a  doubly  perforated  stopper.  In  one  of 
the  holes  is  placed  the  neck  of  the  glass  funnel,  the  upper 
rim  of  which  is  ground  smooth,  and  the  other  is  fitted 
with  a  glass  tube,  bent  at  a  right  angle.  A  thick  wooden 
cover,  with  a  ring  of  rubber  on  the  lower  side,  is  placed 
upon  the  funnel,  closing  it  air-tight.  In  the  centre  of  the 
lid  is  fitted  a  glass  tube,  also  bent  at  a  right  angle,  and 
connected  with  another  tube  by  a  rubber  hose.  Either 
filtering  paper  or  fine  cotton  is  used  as  a  filtering  sub¬ 
stance,  of  which  a  plug  is  formed  in  the  lower  part  of  the 
cone  of  the  funnel,  and  lightly  pressed  into  the  tube  of 
the  funnel.  The  air  in  the  bottle  is  displaced  by  the  fluid 
dropping  into  it,  and  escapes  into  the  funnel,  where  it 
absorbs  the  vapor  of  the  fluid,  but  absorbs  nothing  after 
it  is  once  saturated.  While  evaporation  goes  on  con¬ 
stantly  when  an  open  funnel  is  used,  it  is  entirely  checked 
by  using  this  apparatus.  When  it  is  observed  that  the 
pores  of  the  filter  become  very  much  choked  up,  the 
contents  of  the  filter  are  allowed  to  run  off  and  the  fil¬ 
tering  material  is  changed. 


196 


THE  MANUFACTURE  OF  VARNISHES. 


SPIRIT  GOLD-LAC  VARNISHES.— L  Pulverize 
66  parts  of  shellac  and  133  parts  of  gamboge.  Rub  up 
the  powder  with  8  parts  of  dried  saffron,  and  dissolve  the 
whole  in  266  parts  of  alcohol  in  a  flask  tied  up  with  a 
piece  of  perforated  bladder,  by  placing  it  in  a  water  bath, 

II.  Treat  the  following  ingredients  in  the  same  man¬ 
ner  as  above:  Thirty-three  parts  of  shellac,  16  parts  of 
dragon’s  blood,  a  like  quantity  of  turmeric,  and  8  parts 
of  gamboge  dissolved  in  200  to  266  parts  of  alcohol. 

III.  Thirty-three  parts  of  shellac,  4  parts  of  dragon’s 
blood,  and  2  parts  of  saffron,  are  digested  in  800  to  1,200 
parts  of  alcohol  for  8  days  in  the  sun,  and  then  filtered. 

GOLD-LAC  VARNISH  WITH  SHELLAC  AND 
OTHER  RESINS. — 1.  Mix  133  parts  of  seed  lac,  a  like 
quantity  of  sandarac,  66  parts  of  turpentine,  16  parts  of 
dragon’s  blood,  and  2  parts  each  of  gamboge  and  tur¬ 
meric,  with  133  to  166  parts  of  pulverized  glass,  and 
digest  the  whole  in  1,600  parts  of  alcohol. 

H.  Pour  500  to  600  parts  of  alcohol  over  30  parts  of 
seed  lac,  60  parts  of  sandarac,  a  like  quantity  of  elemi,  30 
parts  of  dragon’s  blood,  20  parts  each  of  turmeric  and 
gamboge,  1  part  of  saffron,  and  60  to  100  parts  of  pul¬ 
verized  glass. 

HI.  Take  133  parts  of  shellac,  50  parts  of  sandarac,  33 
parts  of  mastic,  in  grains,  100  parts  of  yellow  resin,  33 
parts  each  of  yellow  amber  and  dragon’s  blood,  24  parts 
each  of -gamboge  and  turmeric,  and,  if  a  deeper  color  is 
desired,  30  parts  of  aloes,  and  pour  2,000  parts  of  alcohol 
over  the  whole. 

GOLD  VARNISH  WITHOUT  LAC.— Dissolve  33 
parts  of  copal,  16  parts  of  white  boiled  turpentine,  and  4 
of  camphor  in  alcohol.  Then  prepare  a  solution  of  33 
parts  of  sandarac,  16  parts  of  mastic,  8  parts  of  dragon’s 
blood,  16  parts  of  gamboge,  8  parts  of  annotto,  and  4 


ROBERT  GAN2. 


Or.  J.  fct.  sENNER. 


THE 


Nalional  Prayisioier  Palilisliii  Coiaay, 

ROBERT  GANZ  &  CO.,  Proprietors. 

NEW  YORK  :  CHICAGO  ; 

384-386  PEARE  STREET,  No.  11  RIAETO  BUIEDING, 

Cor.  of  Beckman.  Adjoining  Board  of  Trade. 


The  national  PROVISIONER, 

THE  ORGAN  OF  THE 

Provision  and  Meat  Industries 

OF  THE 

UNITED  STATES  AND  CANADA. 


Chicago,  New  York,  'Roston,  Philadelphia,  Cincinnati,  Kansas 
City,  St.  Eouis,  Eondon,  England. 


PUBLISHED  EVERY  SATURDAY. 


SUBSCRIPTION  PRICE; 

In  the  United  States  and  Canada,  -  -  $4.00  Per  Annum. 
In  Foreign  Countries,  .  _  .  _  _  $5.00  Per  Annum. 

(Postage  Prepaid.) 


PUBLISHERS  OF  THE 

Pork  Packers’  Handbook  and  Directory 

OF  THE 

MEAT  AND  PROVISION  TRADES. 

440  Pages.  Price,  $10.(X). 

The  Manufacture  of  Cottonseed  Oil 

AND 

ALLIED  PRODUCTS. 

95  Pages.  Price,  $3.00. 


XIII. 


198 


THE  MANUEACTURE  OF  VARNtSkES. 


parts  aloes  in  spirit  of  wine,  and  mix  the  two  solutions 
together. 

GOLD-LAC  VARNISHES  WITH  OIL  OF  TUR¬ 
PENTINE  AND  OIL  OF  LAVENDER  (from  Lavan¬ 
dula  spica). — 1.  Without  Linseed  Oil  Varnish.  Boil  66 
parts  of  mastic,  a  like  quantity  of  sandarac,  and  4  parts 
of  turpentine,  with  100  parts  of  oil  of  lavender  over  a  coal 
fire;  then  add  33  parts  of  aloes  and  some  resin,  and  heat 
the  whole  until  a  small  feather  dipped  into  the  mixture 
ignites. 

H.  With  an  Addition  of  Linseed  Oil  Varnish.  1. 
Dissolve,  with  the  aid  of  a  water-bath,  16  parts  of  amber, 
33  parts  of  shellac,  16  parts  of  sandarac,  33  parts  of  aloes, 
4  parts  of  gamboge,  and  2  parts  of  dragon’s  blood,  in  266 
parts  of  oil  of  turpentine,  and  then  add  a  few  drops  of 
strong  linseed-oil  varnish. 

2.  Pulverize  266  parts  of  amber  and  66  parts  of  stick 
lac.  Dissolve  the  powder  in  266  parts  of  hot  linseed-oil 
varnish  and  400  to  533  parts  of  hot  oil  of  turpentine,  pre¬ 
viously  colored  with  66  parts  each  of  gamboge,  dragon’s 
blood  and  annotto,  and  16  parts  of  saffron. 

3.  Mix  133  parts  of  stick  lac,  a  like  quantity  of  sanda¬ 
rac,  16  parts  of  dragon’s  blood,  2  parts  of  gamboge,  and 
166  parts  of  pulverized  glass,  and  digest  the  mixture  in 
500  parts  each  of  oil  of  turpentine  and  linseed-oil  varnish. 

All  the  foregoing  recipes  have  been  tested  and  can  be 
highly  recommended. 

WALTON’S  PROCESS  OF  PREPARING  LIN¬ 
SEED-OIL  VARNISH  consists  mainly  in  exposing  the 
linseed  oil  to  the  action  of  air,  whereby  it  is  converted 
into  a  resinous  mass,  which,  dissolved  in  wood  spirit  or 
alcohol,  furnishes  a  quickly  drying  varnish.  Clear  lin¬ 
seed  oil  is  mixed  with  a  siccative,  5  to  10  per  cent  of  ace¬ 
tate  of  lead  being  the  most  suitable.  The  mixture  is  then 
passed  through  a  tube  in  which  the  oil  is  conveyed  by 


THE  MANUFACTURE  OF  VARNISHES. 


199 


means  of  a  force  pump  into  the  reservoir  provided  with  a 
perforated  bottom.  The  oil  passes  down  through  this 
bottom,  and  falls  in  jets  or  drops  through  the  column, 
whereby  it  comes  in  contact  with  air  forced  in  by  means 
of  a  blower.  Two  sides  of  the  column  are  constructed  of 
glass  to  allow  the  entrance  of  light,  which  exerts  also  a 
bleaching  effect  upon  the  oil.  The  object  is  to  distribute 
the  air  in  the  apparatus  over  the  hollow  column,  while 
the  other  is  to  allow  the  air  to  pass  out  and  to  retain  par¬ 
ticles  of  oil.  The  current  of  air  need  not  be  very  strong, 
but  a  constant  renewal  of  the  air  in  the  apparatus  is  ab¬ 
solutely  required.  The  oil  falls  into  the  reservoir  be¬ 
neath  which  is  a  space  heated  from  212°  to  300°  Fahren¬ 
heit  by  the  introduction  of  steam;  the  higher  the  tem¬ 
perature  the  quicker  will  be  the  conversion  of  the  oil; 
there  is  a  pipe  through  which  the  oil  is  re-conveyed  to 
the  pump,  by  which  it  is  again  forced  into  the  reservoir, 
drops  down  through,  and  so  on  until  it  has  become  suffi¬ 
ciently  changed.  On  the  upper  end  is  a  small  cylinder 
containing  a  valve,  which  is  connected  with  a  lever  loaded 
in  proportion  to  the  pressure  which  is  to  be  exerted  in 
the  reservoir.  The  rod  is  connected  in  such  a  manner 
with  a  cock  on  the  pipe  that,  when  the  valve  rises  too 
high,  in  consequence  of  too  strong  a  pressure,  communi¬ 
cation  between  the  pump  and  the  reservoir  is  interrupted. 

SEVERAL  UNIVERSAL  FURNITURE  VAR¬ 
NISHES. — I.  Dissolve  240  parts  of  sandarac,^60  parts 
of  seed  lac,  and  120  parts  of  resin  in  1,500  parts  of  spirit 
of  wine,  and  compound  the  solution  with  180  parts  of 
Venetian  turpentine. 

II.  Compound  180  parts  of  naphtha  with  30  parts  of 
virgin  wax.  Apply  the  varnish  warm  and  polish  with  a 
woolen  rag. 

III.  Boil  500  parts  of  white  wax  in  a  solution  of  750 
parts  of  potash  in  warm  water  for  ^  hour,  and,  when  the 


200 


THE  MANUFACTURE  OF  VARNISHES. 


lye  has  become  cold,  skim  off  the  wax  which  floats  on  the 
surface.  Apply  the  wax  to  the  furniture,  and  by  rubbing 
it  an  hour  afterwards  with  a  woolen  cloth,  a  beautiful 
lustre  will  be  the  result. 

IV.  Melt  120  parts  of  yellow  wax  and  a  little  pulver¬ 
ized  resin,  and  compound  this  with  60  parts  of  warm  oil 
of  turpentine  or  spirits  of  turpentine.  Rub  the  furniture 
with  this  by  means  of  a  woolen  rag,  which  will  give  it  a 
beautiful  lustre. 

BALLOON  VARNISH. — Cut  up  500  parts  of 
caoutchouc,  and  let  it  digest  in  3,000  parts  of  oil  of  tur¬ 
pentine  for  7  days,  putting  the  vessel  in  a  warm  place; 
then  heat  the  mixture  in  a  water-bath  until  it  is  entirely 
homogeneous,  add  2,000  parts  of  warm  drying  oil  pre¬ 
viously  boiled,  mix  intimately,  and  strain  the  compound 
as  soon  as  it  is  cold.  The  above  recipes  have  been  tested, 
and  can  be  highly  recommended. 

COPAL  VARNISH  WITH  SPIRIT  OF  SAL-AM¬ 
MONIAC. — Convert  copal  into  a  coarse  powder  and 
gradually  pour  spirit  of  sal-ammoniac  over  it  until  the 
whole  is  swelled  up  to  a  thick,  transparent  mass.  Heat 
this  to  100°  Fahrenheit,  then  mix  it  gradually  with  alco¬ 
hol,  75  to  80  per  cent  strong;  shake  it  thoroughly,  and 
finally  add  more  alcohol  to  give  the  mixture  the  requisite 
consistency. 

CHINESE  VARNISH. — Dissolve  60  parts  of  shellac 
and  a  piece  of  camphor  the  size  of  a  hazel-nut  in  1,000 
parts  of  spirit  of  wine,  by  placing  the  vessel  containing 
it  in  the  sun  or  in  hot  ashes  for  24  hours,  shaking  the 
bottle  from  time  to  time;  then  strain  the  fluid.  Let  the 
varnish  stand  quietly  for  24  hours,  and  then  pour  it  off 
carefully  from  the  sediment;  the  latter  may  be  used  for 
the  first  coat. 

INCOMBUSTIBLE  VARNISH  FOR  WOOD.— 
An  application  of  a  solution  of  equal  parts  of  alum  and 


THE  MANUFACTURE  OF  VARNISHES. 


201 


isinglass  to  the  place  exposed  to  the  flame  prevents  igni¬ 
tion,  but  not  the  transmission  of  heat.  By  coating  a 
wooden  vessel  with  this  varnish,  fluids  may  be  boiled  in 
them  over  an  ordinary  fire. 

VARNISH  FOR  WOOD  NOT  ACTED  UPON 
BY  BOILING  WATER. — Boil  in  an  untinned  copper 
boiler  750  parts  of  linseed  oil.  Suspend  in  this,  in  a 
bag,  which  must  not  touch  the  bottom,  150  parts  of  lith¬ 
arge  and  90  parts  of  pulverized  minium.  Let  the  oil  boil 
until  it  has  assumed  a  dark-brown  color;  then  remove 
the  bag,  and  replace  it  by  one  containing  7  to  8  bulbs  of 
garlic.  Now  melt  500  parts  of  pulverized  amber  in  60 
parts  of  linseed  oil  over  a  strong  fire,  add  it  while  boiling 
to  the  prepared  linseed  oil  and  let  it  boil  for  2  or  3  min¬ 
utes  longer,  stirring  it  vigorously.  Then  take  it  from  the 
fire,  allow  it  to  settle,  pour  off  the  clear  liquid,  and,  when 
cold,  put  it  in  bottles,  which  should  be  hermetically . 
closed. 

To  use  this  varnish,  polish  the  wood  first  and  give  it 
the  desired  color;  for  instance,  nut-brown,  by  laying  on 
a  thin  coat  of  a  mixture  of  lampblack  and  oil  of  turpen¬ 
tine.  When  the  stain  is  dry,  apply  four  coats  of  the  var¬ 
nish  with  a  fine  sponge,  allowing  one  coat  to  dry  before 
laying  on  the  next. 

VARNISH  FOR  EARTHEN-WARE  VESSELS.— 
Mix  equal  parts  of  pulverized  glass  and  soda;  dry  the 
mixture  over  a  strong  fire,  and  spread  it  upon  the  surface 
of  the  burnt  vessels  while  they  are  still  hot. 

JAPANESE  TRANSPARENT  LAC  VARNISH.— 
Dissolve  30  parts  of  copal  ajad  2  parts  of  camphor  in  120 
parts  of  oil  of  turpentine  and  30  parts  of  oil  of  lavender. 

JAPANESE  BLACK  LAC  VARNISH.— 1.  Take 
120  parts  of  burnt  umber,  60  parts  of  genuine  asphaltum, 
and  3,000  parts  of  boiled  oil.  Dissolve  the  asphaltum  in 
a  small  portion  of  the  oil  with  the  aid  of  heat,  then  add 


202 


THE  MANUFACTURE  OF  VARNISHES. 


the  umber,  previously  rubbed  up  with  oil,  and,  finally,  the 
remaining  oil;  mix  the  whole  thoroughly,  allow  it  to 
cool,  and  thin  with  oil  of  turpentine.  This  varnish  is 
very  elastic. 

II.  Dissolve  1  part  of  shellac  in  4  of  wood  spirit,  and 
color  with  lampblack. 

VARNISH  FOR  FANS,  FANCY  BOXES,  ETC.— 
Dissolve  60  parts  of  mastic  and  240  parts  of  sandarac  in 
1,500  parts  of  spirit  of  wine,  and  compound  the  solu¬ 
tion  with  120  parts  of  Venetian  turpentine. 

VARNISH  FOR  UMBRELLAS.— Boil  2  parts  of 
turpentine  and  1  of  pulverized  litharge  in  2  to  3  of  lin¬ 
seed  oil.  This  varnish  is  applied  with  a  brush  and  dried 
in  the  sun. 

BLACK  VARNISH  FOR  TINSMITHS.— Mix  fine 
lampblack  or  Frankford  black  with  a  solution  of  shellac, 
or  with  a  solution  of  1  part  of  asphaltum  in  3  of  oil  of  tur¬ 
pentine,  and  then  add  some  linseed  oil  and  minium. 

GOLD  VARNISH  ON  IRON.— Boil  in  an  earthen¬ 
ware  pot  90  parts  or  more  of  linseed  oil,  60  parts  of  tar¬ 
tar,  60  parts  of  hard-boiled  yelk  of  egg,  15  parts  of  aloes, 
^  part  of  saffron  and  1-10  part  of  turmeric,  and  apply  the 
fluid  to  the  iron. 

PITCH  VARNISH  FOR  BUILDINGS.  —  One 
pound  of  linseed  oil,  150  parts  of  pitch,  and  120  parts  of 
litharge  are  boiled  over  a  coal  fire  and  stirred  until  they 
are  intimately  mixed.  Apply  one,  or,  if.  necessary,  sev¬ 
eral  coats  of  this  varnish  to  the  weather  side  of  the  build¬ 
ings,  which  will  render  them  impervious  to  moisture. 
The  above  quantities  suffice  to  give  4  coats^  to  18 
square  feet  of  surface.  Shingle  roofs  coated  with  this 
varnish  last  at  least  twice  as  long  as  ordinary. 

SPIRIT  VARNISH  FOR  VIOLINS  AND  OTHER 
MUSICAL  INSTRUMENTS. — Dissolve  over  a  moder¬ 
ate  fire  120  parts  of  sandarac,  60  parts  of  shellac,  a  like 


THE  MANUFACTURE  OF  VARNISHES. 


203 


quantity  of  mastic,  and  30  parts  of  elemi,  in  1,500  parts 
of  highly  rectified  spirit  of  wine,  and  after  the  solution 
has  boiled  up  several  times,  add  60  parts  of  Venetian 
turpentine. 

BLACK  VARNISH  FOR  ZINC. — Equal  parts  of 
chlorate  of  potassium  and  blue  vitriol  are  dissolved  in  36 
times  as  much  warm  water,  and  the  solution  allowed  to 
cool.  If  the  sulphate  of  copper  used  contains  iron,  it  is 
precipitated  as  a  hydrated  oxide  and  can  be  removed  by 
decantation  or  filtration.  The  zinc  castings  are  then  im¬ 
mersed  for  a  few  seconds  in  the  solution  until  quite  black, 
rinsed  off  with  water,  and  dried.  Even  before  it  is  dry 
the  black  coating  adheres  to  the  article  so  that  it  may  be 
wiped  dry  with  a  cloth.  If  copper-colored  spots  appear 
during  the  operation,  the  solution  is  applied  to  them  a 
second  time,  and  after  awhile  they  turn  black,  when  the 
article  is  washed  and  dried.  On  rubbing,  the  coating  ac¬ 
quires  a  glittering  appearance  like  indigo,  which  disap¬ 
pears  on  applying  a  few  drops  of  linseed-oil  varnish  or 
“wax-milk,”  and  the  zinc  then  has  a  deep-black  color 
and  gloss.  The  “wax-milk”  is  prepared  by  boiling  1 
part  of  yellow  soap  and  5  of  Japanese  wax  in  21  of  water 
until  the  soap  dissolves.  When  cold,  it  has  the  consist¬ 
ency  of  a  salve,  and  will  keep  in  closed  vessels  for  an  in¬ 
definite  time.  It  can  be  used  for  polishing  carved  wood 
and  for  waxing  ball-room  floors,  as  it  is  cheaper  than  the 
solution  of  wax  in  turpentine,  and  does  not  stick  or  smell 
disagreeably  like  the  latter. 

PARISIAN  WOOD  VARNISH.— This  celebrated 
varnish  is  prepared  by  dissolving  1  part  of  shellac  in  3  or 
4  of  alcohol  of  '92  per  cent,  on  the  water-bath,  and 
cautiously  adding  distilled  water  until  a  curdy  mass 
separates,  which  is  collected  and  wrapped  in  linen.  The 
liquid  is  filtered  through  paper,  all  the  alcohol  removed 
by  distillation  from  the  water-bath,  and  the  resin  re- 


204 


THE  MANUFACTURE  OF  VARNISHES. 


moved  and  dried  at  212°  Fahrenheit  untif  it  ceases  to 
lose  weight.  It  is  then  dissolved  in  double  its  weight  of 
alcohol,  of  at  least  96  to  98  per  cent,  and  the  solution 
perfumed  with  lavender  oil. 

FURNITURE  VARNISH.— Heat  gently,  with  con¬ 
stant  stirring,  8  parts  of  white  wax,  2  of  resin,  and  ^  of 
Venetian  turpentine;  pour  the  mixture  into  a  glazed 
stone  pot  and  add,  while  it  is  yet  warm,  3,500  parts  of 
rectified  oil  of  turpentine.  After  standing  for  24  hours 
the  mass  forms  a  soft,  buttery  substance,  and  is  ready  for 
use.  The  articles  to  be  varnished  must  be  carefully 
cleansed  with  soap  and  water,  and  then  dried  before  ap¬ 
plying  the  varnish.  The  polish  obtained  is  not  quite  as 
brilliant  as  that  obtained  by  shellac  varnish,  but  has  a 
peculiar  chaste  appearance. 

TO  LACQUER  FLOWERS.— Pulverize  40  parts  of 
sandarac,  15  parts  of  mastic,  and  2  parts  of  camphor,  and 
put  the  powder  into  a  long-necked  flask;  then  pour  1,000 
parts  of  rectified  spirit  of  wine  over  it,  and  place  the  flask 
in  a  moderately  warm  place,  shaking  it  at  first  frequently, 
and  then  allowing  it  to  stand  quietly  so  that  the  fluid 
may  settle.  Flowers,  plants,  and  herbs  may  be  coated 
with  this  varnish.  Flowers  retain  not  only  their  beau¬ 
tiful  colors,  but  are  also  protected  against  the  ravages  of 
insects.  This  varnish  is  also  adapted  for  coating  maps, 
playing-cards,  copper  prints,  and  pictures. 

WHITE  UNCHANGEABLE  LACQUER  FOR 
LEATHER. — Artificially  prepared  carbonate  of  baryta 
is  rubbed  up  with  very  light  linseed-oil  varnish,  and  the 
compound  applied  to  the  leather.  On  this  is  laid  a  coat 
prepared  from  carbonate  of  baryta  and  white  copal  var¬ 
nish,  When  dry,  the  lacquer  is  pumiced  with  elutriated 
pumice-stone  and  a  piece  of  felt,  and  then  polished  with 
elutriated  bone-ash.  The  white  color  of  this  lacquer 


THE  MANUFACTURE  OF  VARNISHES. 


205 


is  not  changed  in  the  least  by  sulphuretted  or  other  ex¬ 
halations,  which,  as  is  well  known,  darken  white  lead. 

TO  POLISH  CARVED  WOOD.— Dissolve  1  part 
of  seed  lac  and  1  of  transparent  resin  in  9  of  spirit  of 
wine.  This  polish  must  be  applied  warm,  and  the  article 
to  be  polished  must  be  heated  if  possible. 

A  beautiful  French  polish  is  obtained  by  using  the  fol¬ 
lowing  ingredients:  700  parts  spirit  of  wine,  15  parts  of 
copal,  7  parts  of  gum-arabic,  and  30  parts  of  shellac. 
The  resins  are  first  pulverized  and  bolted  through  a  piece 
of  muslin.  The  powder  is  placed  in  a  flask,  the  spirit  of 
wine  poured  over  it,  and  the  flask  corked.  By  putting 
the  flask  in  a  moderately  warm  place,  the  solution  will  be 
accomplished  in  two  or  three  days.  It  is  then  strained 
through  a  piece  of  muslin  and  kept  in  hermetically  closed 
bottles.  This  polish  gives  a  beautiful  appearance  to  the 
carvings,  and  a  gloss  and  richness  of  color  which  cannot 
be  obtained  by  any  other  means.  It  is  especially  adapted 
for  polishing  fine  furniture,  dnd  for  this  purpose  is  to  be 
preferred  to  all  other  polishes.  To  give  to  articles 
polished  with  this  lacquer  the  finest  finish  possible,  the 
following  preparation  is  used :  Put  8  parts  of  shellac  and 
a  like  quantity  of  benzoin,  and  350  parts  of  rectified  spirit 
of  wine  into  a  flask,  keep  this  in  a  warm  place  until  all 
the  gum  is  dissolved,  and  shake  it  vigorously.  To  the 
cold  solution  add  a  small  portion  of  the  best  poppy-seed 
oil,  which  should  be  as  clear  as  water;  mix  all  intimately 
together  and  keep  it  for  use. 

PARISIAN  BRONZE  LACQUER.— Dissolve  1  part 
of  shellac  in  8  to  10  of  alcohol,  and  add  to  the  solution  ^ 
part  of  camphor,  rubbed  up  with  a  few  drops  of  lavender 
oil. 

BLACK  POLISH  ON  IRON  AND  STEEL.— A 
beautiful  black  polish  is  obtained  by  boiling  1  part  of  sul¬ 
phur  with  10  of  oil  of  turpentine,  but  it  has  a  disagreeable 


20(5 


THE  MANUFACTURE  OF  VARNISHES. 


odor.  A  coat  as  thin  as  possible  is  laid  on  the  article  to 
be  polished,  which  is  then  held  over  the  flame  of  an  alco¬ 
hol  lamp  until  the  black  polish  makes  its  appearance. 

A  NEW  VARNISH  (patented  in  Germany),  which 
serves  as  a  substitute  for  linseed  oil  or  oil  of  turpentine, 
is  prepared  in  the  following  manner:  100  parts  of  resin 
free  from  oil  of  turpentine,  20  of  crystallized  soda,  and  50 
of  water  are  heated  together,  and  then  intimately  mixed 
with  250  parts  of  water,  containing  24  of  aqua  ammonia. 
The  coloring  substances  are  rubbed  up  with  this  prepara¬ 
tion  without  an  addition  of  linseed  oil,  or  oil  of  turpen¬ 
tine;  they  ,  dry  easily  without  a  siccative,  and  can  be 
coated  with  lacc|uer.  This  varnish  becomes  very  hard; 
resists  the  action  of  water  and  atmospheric  influences, 
and  is  about  one-third  cheaper  than  ordinary  varnish. 

PARISIAN  BOOKBINDERS’  LACQUER.— Dis¬ 
solve  on  the  water-bath  360  parts  of  shellac  and  2  parts 
each  of  camphor  and  loaf  sugar  in  3,000  parts  of  alcohol 
of  66  per  cent.  Eilter  the  solution  through  blotting- 
paper;  distill  off  one-half  of  the  alcohol,  and  add  to  the 
residue,  while  yet  warm,  a  trace  of  oil  of  cinnamon. 

EXCELLENT  GLASS-LIKE  VARNISH.— Dis¬ 
solve,  at  a  moderate  heat,  4  parts  of  camphor,  60  parts  of 
sandarac,  15  parts  each  of  Venetian  turpentine  and  oil 
of  turpentine,  and  4  parts  of  white  sugar,  in  400  parts  of 
spirit  of  wine  of  96  per  cent,  and  clarify  the  solution  by 
allowing  it  to  stand  for  some  time.  In  using  the  varnish 
expose  the  article  to  be  coated  to  a  gentle  heat,  and  then 
apply  the  solution,  which,  when  it  becomes  dry,  will  form 
a  beautiful,  glass-like  coat. 

VARNISH  EOR  WOOD  NATURALLY  COL¬ 
ORED  OR  STAINED. — Pulverize  and  dissolve  3  parts 
of  light-colored  shellac,  2  of  sandarac,  2  of  white  resin, 
and  I  of  camphor,  in  24  of  alcohol  of  80  per  cent.  Put, 
first,  the  shellac,  sandarac,  and  camphor  in  the  alcohol, 


THE  MANUFACTURE  OF  VARNISHES. 


207 


tie  up  the  vessel  with  a  piece  of  wet  bladder  and  shake 
it  for  half  an  hour;  then  add  the  resin,  and  let  the  mix¬ 
ture  boil  up  several  times  in  a  suitable  vessel.  Filter  the 
ready  varnish,  while  yet  warm,  throug^h  cotton  or  felt, 
and  to  clarify  it,  let  it  stand  for  12  hours  in  a  well-closed 
bottle.  No  more  varnish  than  is  to  be  used  in  two  or 
three  days  should  be  prepared  at  one  time,  since  age  im¬ 
pairs  its  beauty  and  hardness. 

COLORLESS  VARNISH. — Boil  500  parts  of  linseed 
oil  with  1,000  parts  of  water  for  two  hours;  then  add  60 
parts  of  silver  litharge,  45  of  sugar  lead,  one  onion,  and 
a  small  piece  of  pumice-stone,  and  then  heat  the  mix¬ 
ture  for  some  time  longer. 

FRENCH  LEATHER  LACQUER.— Boil  15  parts 
of  logwood  shavings  in  120  of  ordinary  water  until  but 
half  the  quantity ' remains;  dissolve  in  this  2  parts  of 
sugar  and  12  of  gum  arabic  and  compound  the  mixture 
with  a  solution  of  ferric  sulphate  until  the  previously 
brown-red  color  of  the  decoction  has  changed  into  a 
violet-blue  tint,  and  finally  add  some  spirit  of  wine. 

CHEAP  LACQUER  FOR  HARNESSES  AND 
CARRIAGE  TOPS. — Soak  2  parts  of  glue  and  then 
liquefy  it  over  a  moderate  fire.  Then  dissolve  3  parts 
of  ordinary  soap  over  a  moderate  fire,  and  add  this  to  the 
solution  of  glue.  About  120  parts  of  water  are  used  for 
dissolving  both  ingredients.  After  the  two  solutions 
have  been  intimately  mixed,  add  3  to  4  parts  of  spirit  var¬ 
nish,  and  finally  stir  into  the  mixture  2  parts  of  good 
wheat  starch,  previously  triturated  with  some  water. 
Now  place  the  pot  containing  the  mixture  over  a  moder¬ 
ate  coal  fire,  and  let  it  evaporate,  although  it  may  also  be 
used  before  evaporation.  The  evaporated  mass,  when  to 
be  used,  is  liquefied  by  adding  beer  or  water.  The  thin¬ 
ner  the  coat  the  more  beautiful  will  be  the  gloss. 


208 


THE  MANUFACTURE  OF  VARNISHES. 


LACQUER  FOR  DRAWINGS.— Dissolve  30  to  40 
parts  of  dammar  in  180  parts  of  acetone  and  then  mix 
40  parts  of  this  solution  with  30  parts  of  thickly-fluid 
collodion. 

TRANSPARENT  LACQUER  FOR  CLOSING 
BOTTLES. — A  process  of  closing  bottles,  which  is  more 
elegant  and  effectual  than  with  tinfoil,  has  recently  been 
introduced  in  France.  The  neck  of  the  bottle  is  dipped 
into  a  tenacious  mass  and  quickly  withdrawn  with  a 
rotary  motion.  It  is  in  this  manner  covered  with  a  trans¬ 
parent  mass,  which  can  be  given  a  still  more  beautiful  ap¬ 
pearance  by  placing  the  monogram  of  the  firm,  or  other 
label,  on  the  neck  of  the  bottle  or  on  the  cork.  The  pre¬ 
paration  consists  of  20  parts  of  resin,  40  of  ether,  60  of 
collodion,  and  any  desired  coloring  matter. 

TAR  VARNISH. — Tar  is  intimately  mixed  with  equal 
parts  of  hydraulic  lime  and  Roman  or  Portland  cement, 
by  heating  the  ingredients  to  158°  Fahrenheit.  The  mix¬ 
ture  remains  thinly  fluid  and  when  dry,  soft  and  flexible. 
This  varnish  is  not  acted  upon  by  acids,  and  protects  the 
wood  from  rotting.  It  is  especially  adapted  for  wood 
under  water,  shingles,  and  water-pipes. 

POLISHING  OF  WOOD. — The  former  practice  of 
pumicing  furniture  with  oil  is  now  supplanted  by  Ross- 
bach’s  patent  (now  expired),  of  pumicing  dry  and  coat¬ 
ing  with  a  mixture  of  285  parts  of  copal,  57  of  oil  of  tur¬ 
pentine,  628  of  infusorial  earth,  and  28  of  umber,  prin¬ 
cipally  used  for  walnut  and  chestnut;  for  rosewood,  car¬ 
mine  is  used  in  place  of  umber;  for  oak,  ochre,  etc.  A 
solution  of  3  parts  of  shellac,  2  of  copal,  and  ^  of  oil  of 
rosemary  in  10  of  alcohol  is  used  as  a  ground  lacquer. 

ELASTIC  LACQUER. — Slake  15  parts  of  lime  with 
20  parts  of  water,  and  add,  while  the  lime  is  yet  warm, 
50  parts  of  the  melted  crude  caoutchouc.  When  cold. 


the  MANUTACTURE  of  VARNtSHES. 


209 


the  lacquer  is  in  the  form  of  a  paste.  It  is  best  applied 
warm. 

black  harness  lacquer. — Dissolve  40  parts 
of  best  shellac,  10  parts  of  sandarac,  and  5  parts  of  mastic 
in  500  parts  of  spirit  of  wine.  To  prevent  the  lacquer 
from  becoming  brittle,  add  to  the  solution  20  to  30  parts 
of  pure  Venetian  turpentine,  and  finally  sufficient  aniline- 
black  (nigrosine),  dissolved  in  water  or  spirit  of  wine. 

PARCHMENT  ELUID  is  prepared  from  gutta¬ 
percha  soaked  and  swelled  up  in  ether.  It  is  used  for 
coating  pictures,  maps,  etc.  The  coat,  if  stained  or  soiled, 
can  be  washed  with  a  moist  sponge.  Crayon  and  char¬ 
coal  drawings  can  be  fixed  by  coating  them  with  this  lac¬ 
quer. 

TO  PROVIDE  BARS  OE  SPRING  STEEL  WITH 
A  COATING  NOT  ACTED  UPON  BY  ACIDS,  AL¬ 
KALIES,  CHLORINE,  AND  STEAM.— The  bars  are 
first  coated  with  copal  or  asphaltum  lacquer  and  dried  at 
a  high  temperature.  They  are  then  wrapped  in  several 
layers  of  strongly-pressed  .  paper,  impregnated  with 
chromium  glue,  and  subjected  to  a  very  strong  pressure, 
and  finally  receive  a  coat  of  the  following  compound: 
Fifty  parts  of  China  clay,  10  of  shellac,  8  of  sandarac,  3 
of  elemi,  2  of  gun-cotton,  0.5  of  camphor,  and  5  of  oil  of 
lavender  (from  Lavandula  spica),  dissolved  in  100  parts 
of  alcohol.  When  half  dry, 'the  bars  are  again  subjected 
to  pressure,  and  when  entirely  dry,  ground. 

ALUMINIUM  PALMITATE  AND  ITS  USES  IN 
DIFFERENT  BRANCHES  OF  INDUSTRY.— 
Aluminium  palmitate,  a  combination  of  alumina  and 
palmitic  acid,  is  a  resinous  substance  of  remarkable  pro¬ 
perties,  making  it  useful  for  many  purposes.  It  melts  at 
a  higher  temperature  than  dammar  and  copal  resin,  and 
is  easily  soluble  in  oil  of  turpentine  and  benzene.  A  so¬ 
lution  of  1  part  of  it  in  5  of  a  solvent  retains  a  lacquer- 


210 


tHE  MANUFACTtrftE  OF  VAftNISHES. 


like,  thickly-fluid  consistency.  The  lacquer  obtained  in 
this  manner  does  not  soak  through  paper,  never  becomes 
brittle,  but  remains  flexible  and  dries  quickly.  It  has  a 
beautiful  silky  gloss,  bears  an  addition  of  any  amount  of 
dammar  and  copal,  obtaining  thereby  greater  gloss  and 
depriving  the  latter  two  resins  of  their  brittleness.  Alum¬ 
inium  palmitate  will,  without  doubt,  be  of  great  import¬ 
ance  in  the  manufacture  of  wall  paper,  lacquers,  artificial 
leather,  water-proof  substances,  etc.  Lacquer  prepared 
from  it  will  be  of  great  value  in  manufacturing  gold  wall 
papers,  and  for  coating  genuine  and  imitation  leather 
hangings,  giving  to  the  latter  the  characteristic  gloss  of 
stamped  leather,  and  preserving  it  in  the  first.  It  fur¬ 
nishes  also  an  excellent  vegetable  glue  which  does  not 
spoil;  is,  and  remains,  entirely  neutral,  and  consequently 
exerts  no  injurious  influence  upon  the  shades  of  the 
colors.  This  makes  it  especially  useful  in  the  manufacture 
of  velvet  wall  paper.  If  used  as  a  sizing  on  cotton  fabrics, 
it  imparts  to  them  a  silky  gloss,  which  does  not  entirely 
disappear  even  after  frequent  washings.  This  sizing,  on 
account  of  its  neutrality  and  entire  indifference,  can  be 
used  for  fabrics  printed  with  the  most  critical  colors  with¬ 
out  injuring  them  in  the  least.  Palmitate  lacquer  is  not 
acted  upon  by  water,  and  can,  therefore,  as  it  remains 
perfectly  flexible,  be  advantageously  used  in  the  manu¬ 
facture  of  artificial  leather,  rubber  tissues,  and  water¬ 
proof  fabrics,  its  property  of  being  inodorous  when  dry 
deserving  special  commendation. 

NEW  METHOD  OF  PREPARING  FAT.  LAC¬ 
QUER  AND  VARNISH,  PATENTED  IN  GER¬ 
MANY  BY  ZIMMERMANN  &  HOLTSWICH. — 
The  resins  are  melted  by  a  current  of  air  heated  above 
the  melting  point  of  the  resins  and  circulating  in  the 
melting  apparatus.  The  products  escaping  in  melting 
are  collected  in  a  cooled  and  closed  receiver.  The  warm 


•tme  manufacture  of  varnishes. 


^11 


current  of  air,  after  it  leaves  the  melting  apparatus,  serves 
to  convert  the  linseed  oil  into  varnish.  The  addition  of 
litharge  is  saved  by  the  use  of  lead  vessels  or  lining  them 
with  sheet  lead.  The  linseed  oil  flows  slowly  down  in  an 
apparatus  through  several  boxes  placed  above  each 
other,  from  whence  it  reaches  a  reservoir  (a  kind  of 
montejus),  is  pumped  up  by  compressed  air  into  another 
vessel,  and  flows  from  this  again  through  the  boxes;  the 
operation  being  repeated  until  it  is  converted  into  var¬ 
nish.  With  this  apparatus,  a  light-colored,  fine  varnish, 
of  excellent  consistency,  equal  to  the  best  English  var¬ 
nish,  is  prepared  in  about  one-quarter  of  the  time  used  in 
the  ordinary  process. 

LIGHT  COPAL  VARNISH  WITH  COAL-TAR 
VARNISH  OIL. — Light  copal  2  parts,  light  resin  1, 
sandarac  and  Venetian  turpentine  each  -J,  varnish  oil  10. 
Pulverize  and  melt  together  the  copal  and  resin,  then  add 
the  sandarac,  and  finally  the  turpentine;  stir  until  all  are 
dissolved;  let  it  cool  somewhat  and  then  add  the  varnish 
oil,  first  in  small  portions  and  finally  the  remainder.  Fil¬ 
ter  the  varnish  through  cotton. 

LIGHT  PARISIAN  VARNISH  WITH  COAL- 
TAR  VARNISH  OIL. — Light  sandarac  3  parts,  light 
resin  and  mastic  each  1,  Venetian  turpentine  cam¬ 
phor  and  oil  of  lavender  each  1-10,  varnish  oil  12,  abso¬ 
lute  alcohol  2.  jMelt  the  sandarac,  resin  and  mastic  to¬ 
gether,  and  then  add  the  turpentine.  Dissolve  the  cam¬ 
phor  and  oil  of  lavender  in  the  absolute  alcohol,  and  add 
finally  to  the  varnish. 

LIGHT  VARNISH  FOR  LACQUERING  PHO¬ 
TOGRAPHIC  NEGATIVES.— Dammar  1  part,  mas¬ 
tic  sandarac  chloroform  and  varnish  oil  each  10. 
Pulverize  the  resin,  pour  the  chloroform  over  them,  then 
add  the  varnish  oil,  and  digest  the  whole  in  a  sand-bath 
until  all  are  dissolved.  Filter  the  varnish  through  clean 


212 


THfi  MANUFACTURE  OF  VARNISHES. 


cotton  and  keep  it  in  well-closed  bottles.  It  dries  very 
easily. 

ENGLISH  METHOD  OE  VARNISHING 
COACHES. — The  superiority  of  English  work  is  largely 
due  to  the  fact  that  though  the  same  materials  are  used, 
more  care  is  exercised  in  preparing  the  varnishes,  and 
greater  attention  paid  to  preparing  the  woodwork  for 
the  reception  of  the  varnish. 

PUMICING. — Grind  a  smooth  face  on  a  piece  of 
pumice-stone,  then  sift  some  pulverized  pumice-stone 
through  a  hair  sieve,  and  dipping  the  ground  face  of  the 
stone  into  this  powder,  pumice  the  panels  of  the  coach; 
then  cleanse  thoroughly  with  a  brush  and  finish  them 
with  a  cloth. 

PUTTYING. — Before  laying  on  the  ground  color,  all 
holes,  cracks,  and  indentations  must  be  puttied  up.  The 
putty  used  is  prepared  by  mixing  white  lead,  red  lead, 
umber  and  a  little  silver  litharge  with  thick  boiled  linseed 
oil  varnish,  and  adding  a  little  amber  varnish.  Press  the 
putty  into  the  holes  and  cracks  by  means  of  a  wooden 
spatula.  When  the  putty  is  dry,  dip  a  piece  of  pumice- 
stone  in  water  and  grind  the  puttied  places  down  so  that 
they  become  even  with  the  panels. 

SATURATING  THE  PANELS  WITH  OIL.— For 
this  purpose  a  mixture  of  equal  parts  of  linseed  oil  and 
linseed-oil  varnish  is  used.  Pour  both  into  a  pot,  mix 
thoroughly,  make  the  mixture  boiling  hot,  and  then  satu¬ 
rate  the  panels.  When  the  first  coat  is  thoroughly  soaked 
in,  repeat  the  operation,  and  then  allow  it  to  dry  thor¬ 
oughly. 

LAYING  ON  THE  GROUND.— The  ground  color 
is  prepared  by  rubbing  1,500  parts  of  white  lead,  6G  parts 
of  red  lead,  16  parts  of  litharge,  and  83  parts  of  burnt 
umber  with  oil  of  turpentine,  and  diluting  it  with  amber 
lac  varnish.  Do  not  lay  on  the  ground  color  too  thick 


THE  MANUFACTURE  OF  VARNISHES. 


213 


at  one  time,  but  apply  several  thin  coats.  Care  should 
also  be  had  that  the  color  shows  no  lustre;  should  this  be 
the  case,  add  some  oil  of  turpentine. 

PUMICING  THE  GROUND. — Moisten  two  pieces 
of  pumice-stone  with  water,  and  rub  them  against  each 
other  until  they  have  a  smooth  surface;  use  one  of  them 
for  pumicing,  dipping  it  frequently  in  water.  The  pumic¬ 
ing  must  be  done  in  a  circular  direction,  so  that  no  place 
remains  untouched.  The  color  adhering  to  the  pumice- 
stone  is  removed  by  rubbing  with  the  other  piece  after 
both  have  been  dipped  in  water.  While  pumicing  wash 
the  panels  frequently,  with  a  large,  wet  sponge,  and 
finally  dry  them  with  a  white  linen  cloth. 

LAYING  ON  THE  PAINT.— Proceed  in  the  same 
manner  as  for  ground,  with  the  exception  that,  if  the 
color  is  light,  pale  amber  lac  varnish  must  be  used. 

FIRST  PUMICING  OF  THE  PAINT.— Pulver¬ 
ize  some  pumice-stone  and  pass  the  powder  through 
a  hair  sieve.  Roll  a  piece  of  well-fulled  felt  and  tie  it  to 
prevent  its  unrolling  during  pumicing.  Then,  with  the 
felt  moistened  with  water,  and  dipped  into  the  sifted 
pumice-stone  powder,  pumice  the  paint  as  smooth  as 
possible,  rubbing  always  with  a  circular  motion. 

SECOND  PUMIcInG  OF  THE  PAINT.— Calcine 
pumice-stone  by  placing  it  on  a  coal  fire,  then  rub  it  to  a 
fine  powder  with  water  upon  a  stone,  and  allow  it  to  dry. 
Then  rub  it  very  fine  once  more,  and  with  a  piece  of  felt, 
but  not  rolled  together  as  before,  moistened  and  dipped 
into  the  powder,  rub  in  every  direction  until  a  glossy 
surface  results. 

THIRD  PUMICING  OF  THE  PAINT.— For  this 
purpose  white  prepared  buck’s  horn  is  used.  The  work 
is  done  with  a  piece  of  felt  moistened  and  dipped  in  in 
the  same  manner  as  for  the  second  pumicing.  The  paint 
is  then  cleansed  by  washing  with  a  sponge  and  water. 


214 


THE  MANUFACTURE  OF  VARNISHES. 


dried  with  a  soft  linen  cloth,  and  finally  rubbed  with  a 
piece  of  chamois,  until  the  paint  has  a  mirror-like  lustre. 

LAYING  ON  THE  LAC  VARNISH.— In  doing 
this  the  following  rules  must  be  observed. 

1.  Use  only  the  best  brushes,  and  apply  the  lacquer 
in  long  perpendicular  strokes,  taking  care  that  the  coat 
is  everywhere  of  equal  thickness. 

2.  The  lacquer  must  be  applied  cold,  and  the  second 
coat  only  laid  on  after  the  first  is  thoroughly  dry. 

3.  Lacquering  should  only  be  done  in  a  room  pro¬ 
tected  from  dust  and.  vermin;  when  the  lacquer  is  no 
longer  sticky  the  carriage  may  be  brought  into  the  air. 

4.  When  the  carriage  has  been  placed  in  the  sun,  it 
must  be  frequently  turned,  so  that  the  sun  does  not  beat 
too  steadily  against  one  place. 

5.  The  lacquer  should  be  contained  in  a  wide-mouthed 
vessel  so  that  the  brush  can  be  dipped  into  it  without 
hindrance.  Do  not  take  too  much  of  it  on  the  brush; 
after  dipping  it  in,  turn  the  brush  several  times,  and 
strike  it  against  the  side  of  the  vessel. 

6.  Prepare  your  own  lacquer,  for  which  several  tested 
recipes  will  be  found  below,  or  buy  it  only  from  a  well- 
known  firm. 

POLISHING  THE  LACQUER.— Use  a  piece  of 
very  soft,  clean  felt.  Dip  it  first  in  a  little  olive  oil,  and 
4hen  in  prepared  white  buck’s  horn,  and  rub  the  lacquer 
until  it  has  a  lustre  equal  to  a  ground  mirror-plate;  and 
iinally  rub  it  with  a  soft  linen  or  silk  cloth  dipped  in  fine 
.-starch  flour. 

ORDINARY  BODY  CARRIAGE  LACQUER.— 
.Boil  for  four  hours  2  parts  of  the  best  African  copal,  7 
parts  of  clarified  linseed  oil,  and  8  parts  of  turpentine. 
Mix  thoroughly  and  strain.  On  the  other  hand,  boil  as 
usual  2  parts  of  the  best  gum  anime,  5  parts  of  clarified 
linseed  oil,  and  7  parts  of  turpentine.  Strain  while  hot, 


THE  MANUFACTURE  OF  VARNISHES. 


215 


and  put  into  the  pot  used  for  preparing  the  copal  varnish. 
Mix  2  parts  of  the  anime  varnish  with  one  of  copal  var¬ 
nish;  it  will  dry  quicker  and  harder  than’ the  best  body 
copal  varnish,  and  will  polish  very  soon. 

QUICK-DRYING  BODY  COPAL  VARNISH.— 
Boil  200  parts  of  best  copal,  500  parts  of  clarified  linseed 
oil,  6  parts  of  dry  sugar  of  lead,  and  800  parts  of  turpen¬ 
tine  until  viscid,  and  then  strain.  Boil  in  another  pot 
200  parts  of  gum  anime,  500  parts  of  clarified  linseed  oil, 
6  parts  of  sulphate  of  zinc;  strain  while  hot,  and  mix 
equal  parts  of  the  two  varnishes.  This  varnish  will  dry 
in  6  to  7  hours  in  winter,  and  in  3  to  4  in  summer. 

NEIL’S  CARRIAGE  LACQUERS.— I.  Melt  2  parts 
of  best  copal,  add  gradually  10  parts  of  clarified  linseed 
oil;  boil  until  viscid,  then  reduce  it  with  6  parts  of  oil  of 
turpentine,  and  filter. 

11.  Melt  2  parts  of  gum  anime,  add  5  parts  of  clarified 
linseed  oil,  boil  until  viscid,  reduce  with  7  parts  of  oil  of 
turpentine,  and  filter.  The  two  lacquers  can  be  used 
either  by  themselves  or,  in  case  a  quick-drying  lacquer  is 
required,  mixed  in  equal  parts. 

Water  Varnishes. 

This  group  comprises  but  few  and  little  used  varnishes. 

1.  LAC  WATER  VARNISH. — Shellac  6  ounces, 
borax  14  ounces,  water  1  pint.  Boil  together  until  the 
lac  is  dissolved.  If  bleached  lac  is  used  a  white  varnish 
will  be  made;  if  the  orange  shellac,  the  varnish  will  have 
a  pale  brown  color.  This  varnish  makes  a  fair  vehicle 
for  water  colors;  it  is  a  good  paper  varnish,  and  dries 
with  a  fair  lustre,  and  with  a  hard  coat,  which  is  water¬ 
proof.  By  adding  any  of  the  soluble  coal-tar  colors  col¬ 
ored  varnishes  can  be  made. 

2.  GLAZING  VARNISH. — Mix  1  pint  of  white  of 
egg  with  1  pint  of  water.  A  little  carbolic  acid  or  salicylic 


216 


THE  MANUFACTURE  OF  VARNISHES. 


acid,  or,  better,  thymol  should  be  added  to  preserve  this 
varnish.  This  varnish  or  glaze  dries  with  a  fair  amount 
of  lustre.  If,  after  being  applied,  it  be  placed  in  a  hot 
room,  to  dry,  the  coat  will  be  made  more  waterproof. 
Dried  albumen  may  be  used  instead  of  the  white  of  egg 
by  dissolving  1  ounce  in  1  pint  of  water;  only  the  color 
of  the  glaze  is  not  so  good. 

3.  GLUE  VARNISH  is  made  by  dissolving  1  pound 
of  good,  pale  glue  in  2  gallons  of  water.  The  color  of  this 
varnish  depends  very  much  on  the  quality  of  the  glue 
used;  if  the  best  gelatine,  then  a  white  varnish  will  be 
made;  if  a  brown  glue,  then  a  brown  varnish.  This  var¬ 
nish  is  not  very  good,  because  of  the  sticky  coat  it  gives, 
which  is  not  waterproof;  by  adding  just  before  using  a 
small  quantity  of  bichromate  of  potassium  (1  ounce  in  2 
gallons),  the  coat  becomes  nearly  waterproof.  It  is  im¬ 
portant  that  the  bichromate  be  added  only  just  before 
use,  as  it  would  act  on  the  varnish  and  cause  it  to  set  into 
a  gelatinous  unworkable  mass.  This  varnish  forms  the 
basis  of  some  leather  varnishes.  A  little  thymol  or  borax 
may  be  added  as  a  preservative. 

4.  CRYSTAL  WATER  VARNISH.— One  pound  of 
good  white  gum  arabic  and  1  pound  of  glucose  are  dis¬ 
solved  in  3  pints  of  water.  This  dries  hard,  with  a  gloss. 

How  to  Lace  a  Belt. 

Punch  two  rows  of  holes  in  each  end,  placed  zig-zag. 
In  a  three-inch  belt  there  should  be  four  holes  in  each 
end — two  in  each  row.  In  a  six-inch  belt,  seven  holes — 
four  in  a  row  nearest  the  end.  A  ten-inch  belt  should 
have  nine  holes;  the  edges  of  the  holes  should  not  come 
nearer  than  three-quarters  of  an  inch  to  the  sides,  nor 
seven-eighths  of  an  inch  to  the  ends  of  the  belt.  The 
second  row  should  be  at  least  one  and  three-quarter 


THE  MANUFACTURE  OF  VARNISHES. 


217 


inches  from  the  end.  On  wide  belts  these  distances 
should  be  even  greater. 

Begin  to  lace  in  the  centre  of  the  belt  and  take  care  to 
keep  the  ends  exactly  in  line,  and  to  lace  both  sides  with 
equal  tightness.  The  lacing  should  not  be  crossed  on 
the  side  of  the  belt  that  runs  next  to  the  pulley.  In 
taking  up  belts,  observe  the  same  rules  as  in  putting  in 
new  ones. 

Care  should  be  taken  that  the  ends  of  the  belts,  if  to 
be  butted,  are  cut  square  across,  else  a  crook  may  be 
made  in  the  belt. 


Hints  to  Users  of  Belts. 

Horizontal,  inclined  and  long  belts  give  a  much  better 
effect  than  vertical  and  short  belts. 

It  is  asserted  that  the  grain  side  of  a  belt  put  next  to 
the  pulley  will  drive  30  per  cent  more  than  the  flesh  side. 


THE  END. 


A  Practical  Manual 

ON  THE  MANUFACTURE  OF 

Linseed  Oil  and  Varnishes. 


TABLE  OF  CONTENTS. 


THE  MANUFACTURE  OF  LINSEED  OIL. 

PAGE. 

Concerning  the  Various  Ceasses  of  Feaxseed — Con¬ 
ditions  Requisite  in  Linseed  Oie  to  Produce 

Best  Resuets .  i 

Linseed  Oie  Pecueiarities — Consideration  of  the 
Various  Methods  Used  To-Day  to  Produce  Best 

Resuets — The  Oie  Percentage  in  c.ake .  15 

Press  Room  Operations  and  Their  Effect  Upon  the 
Oie  in  Refining— Method  of  Testing  of  a  Var¬ 
nish  Oie  . 41 

Saet  as  a  Refining  Agent  in  Linseed  Oie — Coeor 
Drawback  Which  Appears  in  an  Improperey 

Tre.ated  Oie .  47 

Heating  Kettees — Uniform  Distribution  of  Temper¬ 
ature  IN  an  Oie  Under  Treatment  Essentiae  to 

Success .  54 

Oxidizing  Agents  of  Linseed  Oie  and  Their  Correct 

Use — OxoNizED  Air .  58 

Practicae  Points  Concerning  the  Fieter  Press, 
Whether  for  Oie  or  Varnish  Fietration,  and 
Where  the  Best  Form  of  FTetering  Medium  May 

Be  Obtained .  So 

Economic  Oie  Mieeing — Practicae  Hints  and  Sugges¬ 
tions  TO  Oie  Mieeers .  90 

American  Linseed.  Cake  Versus  Engeish  and  Other 
Foreign  Makes  in  the  Engeish  and  European 

Markets  (with  Anaeyses) .  122 

The  Fieter  Pre.ss  in  Oie  Mieeing — Further  Detaies 

Concerning  Its  Workings,  Etc .  165 

Manufacture  of  Oie  Varnishes .  176 


INDEX  TO  ADVERTISEMENTS. 


PAGE. 

Atlantic  Drier  Co.,  Philadelphia,  Pa  . .  .Inside  Front  Cover 

Bartlett,  C.  O.  &  Co.,  Cleveland,  O .  VIII 

Buckeye  Iron  &  Brass  Works,  Dayton,  O .  175 

Carter,  C.  W.  H.,  New  York.. . . .  VIII 

Devoe,  F.  W.  &  C.  T.  Raynolds  Co.,  New  York .  XVI 

Dopp,  H.  Wm.  &  Son,  Buffalo,  N.  Y .  XVIII 

Enequist,  Erik,  New  York .  XX 

Feuchtwanger,  D.  &  Co.,  New  York . XVIII 

Hohmann  &  Maurer  Mfg.  Co.,  Rochester,  N.  Y.  .  - .  XV 

Imhauser,  E.,  New  York . .  .  .  XX 

Johnson,  John  &  Co.,  New  York. .  X 

Keasbey,  Robert  A.,  New  York  . . XVII 

Lane,  J.  H.  &Co.,  New  York . Inside  Back  Cover 

Listers  Agricultural  Chemical  Works,  New  York..  .  XIV 

Manhattan  Spirit  Co.,  Buffalo,  N.  Y .  XX 

National  Provisioner  Publishing  Co.,  New  York, 

VII,  XVII,  12 1  and  197 

Niles  Tool  Works  Co.,  Hamilton,  O .  XIX 

Patterson,  G.  W.  S.  &  Co.,  New  York . . . XVIII 

Perkins,  J.  T.  Co.,  Brooklyn,  N.  Y .  IV 

Pr.att  &  Lambert,  New  York .  II 

ScHEEL,  William  H.,  New  York  . .  176 

Sperry,  D.  R.  &  Co.,  Batavia,  III .  XIX 

Stilwell-Bierce  &  Smith-Vaile  Co.,  Dayton,  O .  I 

Sturcke,  H.  E.  &  Co.,  New  York . Inside  Back  Cover 

SuGDEN  Press  Bagging  Co.,  West  Chesterfield,  Mass.  .  IX 

Taber  Pump  Co.,  Buffalo,  N.  Y .  XVI 

Winterbourne,  S.  &  Co.,  New  York .  XX 

Worthington  Pump .  116 


Do  You  I'lake  Black  Varnish? 


IF  so 

Listers  Agricultural 

Chemical  Works, 

159  Front  Street,  New  York, 


Can  furnish  you  with 

ASPHALTUM  of  abso¬ 
lute  purity,  admirably 
suited  for  making  the 


HIGHEST  GRADE 

Black  Varnishes  and  Japans. 


ADDRESS, 

LISTERS  AGRICULTURAL  CHEMICAL  WORKS, 

159  Front  Street,  New  York. 


XIV. 


THERMOMETERS 

For  Oil  Boiling  and  Varnish  Making. 


The  HoIiinann&  Maurer 


ROCHESTER,  N.Y..  U.  S.A. 


MANUFACTURERS  OP  THE 


‘  H 

Special  Thermometers 

FOR 


Linseed  Oil  Crushers  and 
Refiners, 

Cotton  Seed  Oil  Mills, 

Oil  Boiling,  Gum  Melting, 
Mfgrs.  Varnishes  and  Paints, 


Patent  and  Fancy  Colored 
Leather, 

Oil  Cloth  and  Linoleum, 

Printing  Ink,  etc. 

Hand  Thermometers  for 
Testing  Meal,  etc. 


XV. 


TABER  ROTARY  PUMPS. 

SPECIALLY  ADAPTED  TO  PUMPING 

Oils,  Fats,  Brine,  Glue,  Soap,  Etc. 

Put  in  on  Positive 
Guarantee  and  Long 
Trial  Before  Pa3dng. 


PUMPS 

Hot,  Cold,  Thick,  Thin 
FLUIDS. 


TABER  PUMP  CO., 

WRITE  FOR  CATALOGUE  AND  PRICE  LIST.  BUFFALO,  N.  Y, 


F.ff.DEVOE4C.T.RAYllOLD!iCO 


ESTABLISHED  1753. 


Thj  Oldest  and  Largest  Paint  Manufacturing  Concern  in  the  W  ild. 

NEW  YORK,  CHICAGO, 

101-103  Fulton  Street.  176  Randolph  Street. 

Manufacturers  of 

House  Paints,  Fine  Varnishes, 
Brushes,  Artists^  Materials. 


XVI. 


MAGNESIA 

SECTIONAL  COVERINGS. 


54  WARREN  ST.. 


Telephone,  1515 
Gortlandt. 


New  York, 


A  superior  non-con¬ 
ductor  of  heat  for 
Steam  Pipes  and 
all  heated  sur¬ 
faces. 


There  is  Only  One 
MAGNESIA 
COVERING.  - 

BEWARE  OF  IMITATIONS. 


Robt.  A.  Keasbey, 


The  Manofactare  of  Cottonseed  Oil 

- AND - 

ALLIED  PRODUCTS. 

95  Pages.  Price,  $3.00. 


PUBLISHED  BY  THE 

National  Provisioner  Publishing  Co. 


NEW  YORK: 
284-286  Pearl  Street, 
Corner  of  Beekman. 


XVII. 


CHICAGO : 

No  11  Rialto  Building, 
Adjoining  Board  of  Trade. 


THE  LEtDING  HOUSE.  SEIMLESS  JICKETED  GtST-IROG  KETTLES, 

With  and  Without  Agitators. 
Steam  Jacketed  Vacuum  Pans,  Ex¬ 
tract  Kettles,  Lard  Drier,  Mixer  and 
(  ooler.  Full  line  of  Soap-Makers’ 
Machinery. 

H.WM.DOPP&SON, 

MANUFACTURERS  OF 

Soap- Makers’  and  Butchers’ 
Machinery. 

462  Ellicott  Street, 
Buffalo,  N.  Y.,  U.S.  A. 

Write  for  Descriptive  Circular  and  Catalogue.  Mention  this  advertisement. 

By  buying  from  the  Producer,  the  Consumer  saves  the  profits  of  the  Middleman. 

G.  W.  S.  Patterson  &  Co., 

kauri  gum. 

GUM  FIELDS  AND  PACKING  AMERICAN  OFFICE: 

WAREHOUSES:  204  Pearl  Street,  cor.  Maiden  Lane, 

Kaikohe,  New  Zealand.  New  York. 

TELEPHONE,  2728  CORTLANDT. 

A  Full  Line  of  Standard  Gradings  Constantly  on  Hand. 

CORRESPONDENCE  SOLICITED. 

ALBERT  UEL  TODD.  ESTABLISHED  1835.  WILLIAM  H.  OSCANVAN. 

L.  FEUCHTWANGER  &  CO.. 

Manufacturers  and  Importers  of  Miners  of  and  Dealers  in 

CHEMICALS.  MINERALS. 

High  Class  of  Driers  for  Oil  Boilers  and  Varnish  Manufacturers. 
Oxide  of  Manganese,  Borate  of  Manganese,  Chlorides, 
Sulphates,  Etc. 

Publishers  of  Treatises  on  Gems,  Soluble  Glass  and  Fermented  Liquors. 


Factories : 

West  Avenue,  First  and  Flushing  Streets,  Long  Island  City. 
Salesroom  and  Office; 

No.  191  Fulton  Street,  Cor.  Church  Street,  -  -  New  York. 


XVIII. 


FILTER  PRESSES.  .I  ATeI 

For  the  Filtration  of  All  Kinds  of  Product. 


Write  for  Catalogue. 

THE  NILES  TOOL  WORKS  CO., 

Hamilton,  0. 


BRANCHES— New  York,  Philadelphia, 
Boston,  Pittsburgh,  Chicago,  St.  Eouis, 
New  Orleans. 


mCDCDDV  CIITCD  DDCQQ  superior  in  efficiency 
OrCntll  rlLICn  rnLOOi  and  construction. 


The  Patent  Plate  saves  cloths,  produces  a  drier  cake  and  is  altogether  better 
than  the  old  form.  Write  for  Information. 


D.  R.  SPERRY  &  CO..  Batavia,  Ilf. 

Manufacturers  of  VACUUM  PANS,  STEAM-JACKET  KETTLES.  CALDRONS,  Etc. 


XIX. 


ERIK  ENEQUIST, 

IMPORTER  OF 

High-Grade  MANGANESE  OXIDE,  Granulated  or  Powdered. 

MANUFACTURER  OF 
MANGANESE  Borate,  LINOEEATE, 

CARBONATE,  CHLORIDE,  Etc. 

DEALER  IN 

SODA  ASH,  CAUSTIC  SODA,  LITHARGE,  ACETATE  OF  LEAD 
and  CHEMICALS  for  Varnish  Makers,  Oil  Boilers,  and  Color 
Makers. 

Manhattan  Spirit  Co., 

BUFFALO,  N.  Y. 

MANUFACTURERS  OF 

Columbian  Spirit  and 

Refined  Wood  Alcohol. 

Perfect  Substitutes  for  Grain  Alcohol  for  use  in  the  Arts  and  Manufactures. 


Varnish  Gums.  All  Descriptions. 

S.  WINTERBOURNE  &  CO., 

94  PINE  STREET, 

ALFRED  MASON,  Agent.  NEW  YORK. 

Samples  and  Information  on  Application. 


WATCHMAN’S  IMPROVED  TIME  DETECTOR. 


This  instrument  is  supplied 
with  12  and  24  keys,  cover¬ 
ing  either  12  or  24  stations. 
Contains  all  modern  im¬ 
provements. 

SEND  FOR  CIRCULAR. 

E.  IMHAUSER, 

206  B’way,  New  York,  U.  S.  A. 


XX. 


FILTERING  FABRICS  BAGS 


Of  All  Constructions 
for 

SUGAR,  OILS  AND  OTHER  PRODUCTS. 


J.  H.  LANE  8i  CO., 


110  Worth  Street,  -  -  New  York. 


H.  E.  STLRCKE  &  CO., 


National  Provisioner  Analytical  Laboratory. 


Chemical  Analyses 

of  all  Raw  Materials,  Supplies,  Products  and  By- 
Products  in  the  Manufacture  of  Linseed 
Oil  and  Varnishes. 


PROCESSES  INVESTIGATED  AND  TESTED. 


284  Pearl  Street, 

GETTY  CENTER  LIBRARY 


3  3125  00140  2599 


New  York. 


